about_o the_o sun_n as_o tycho_n have_v do_v we_o find_v from_o his_o calculation_n of_o it_o he_o be_v fain_o to_o allow_v it_o a_o quick_a and_o slow_a motion_n in_o its_o orbit_n to_o solve_v the_o phaenomena_n which_o seem_v to_o i_o but_o a_o shift_n that_o will_v serve_v to_o help_v out_o any_o lame_a hypothesis_n whatsoever_o and_o that_o grant_v and_o the_o parallax_n of_o the_o comet_n unknown_a i_o will_v undertake_v very_o easy_o to_o make_v out_o almost_o any_o hypothesis_n which_o be_v the_o fault_n also_o of_o mr._n horox_n his_o hypothesis_n wherein_o he_o suppose_v the_o earth_n to_o be_v move_v about_o the_o sun_n and_o the_o comet_n like_o a_o rocket_n to_o be_v shoot_v out_o of_o the_o sun_n and_o by_o degree_n to_o return_v to_o it_o again_o in_o which_o hypothesis_n indeed_o there_o seem_v to_o be_v much_o more_o reason_n for_o a_o inequality_n of_o motion_n though_o not_o in_o the_o manner_n as_o he_o have_v place_v it_o it_o be_v very_o rational_a that_o the_o motion_n of_o it_o at_o first_o if_o cast_v out_o of_o the_o sun_n shall_v be_v very_o swift_a but_o than_o it_o ought_v likewise_o to_o have_v accelerate_a its_o motion_n in_o the_o same_o manner_n in_o its_o return_n back_o to_o it_o again_o which_o it_o do_v not_o in_o his_o hypothesis_n for_o a_o stone_n or_o any_o other_o heavy_a body_n be_v shoot_v up_o into_o the_o air_n do_v make_v its_o return_n back_o again_o to_o the_o earth_n almost_o by_o the_o same_o degree_n of_o velocity_n by_o which_o it_o ascend_v from_o it_o almost_o i_o say_v because_o the_o resistance_n of_o the_o air_n do_v so_o far_a impede_fw-la the_o motion_n of_o the_o body_n through_o it_o that_o it_o never_o suffer_v it_o to_o acquire_v the_o same_o degree_n of_o velocity_n with_o which_o it_o be_v first_o shoot_v upward_o this_o be_v sufficient_o evident_a from_o a_o pendulum_n which_o if_o it_o be_v throw_v upward_o and_o be_v suffer_v to_o return_v back_o it_o will_v never_o rise_v again_o on_o the_o opposite_a side_n to_o a_o equal_a height_n with_o that_o it_o descend_v from_o on_o that_o side_n towards_o which_o it_o be_v throw_v but_o beside_o in_o his_o hypothesis_n he_o seem_v to_o take_v no_o notice_n at_o all_o of_o the_o latitude_n of_o the_o comet_n which_o seem_v to_o carry_v it_o much_o far_o off_o from_o the_o sun_n when_o he_o suppose_v it_o to_o be_v return_v near_o and_o indeed_o upon_o the_o whole_a his_o hypothesis_n seem_v rather_o a_o product_n of_o chance_n than_o of_o any_o contrivance_n for_o he_o in_o endeavour_v to_o set_v off_o the_o longitude_n of_o the_o comet_n according_a to_o tycho_n table_n and_o to_o trace_v its_o way_n by_o suppose_v the_o earth_n annual_a motion_n make_v use_n always_o of_o the_o same_o radius_fw-la to_o set_v off_o the_o aspect_n or_o apparent_a angle_n of_o it_o with_o the_o sun_n his_o line_n of_o chord_n he_o make_v use_v of_o do_v always_o direct_a the_o point_n of_o his_o compass_n to_o the_o place_n where_o he_o situate_v the_o comet_n as_o may_v be_v easy_o find_v by_o examine_v the_o nine_o figure_n where_o you_o may_v find_v that_o he_o place_v the_o comet_n always_o equal_o distant_a from_o the_o earth_n and_o that_o distance_n be_v always_o equal_a to_o the_o distance_n of_o the_o sun_n which_o have_v so_o many_o inconvenience_n and_o improbability_n that_o i_o shall_v not_o insist_v far_o on_o it_o especial_o since_o i_o do_v not_o find_v that_o he_o bestow_v any_o far_a pain_n in_o explicate_v or_o cultivate_v this_o his_o hypothesis_n than_o only_o the_o bare_a delineation_n of_o this_o nine_o figure_n but_o to_o return_v to_o tycho_n hypothesis_n if_o that_o be_v true_a why_o do_v not_o the_o comet_n again_o appear_v after_o a_o certain_a space_n of_o time_n and_o why_o can_v not_o he_o have_v foretell_v when_o it_o shall_v again_o appear_v as_o well_o as_o he_o can_v predict_v the_o appearance_n of_o venus_n about_o who_o orb_n he_o suppose_v it_o to_o circulate_v i_o shall_v pass_v by_o several_a other_o very_a material_a objection_n that_o may_v be_v make_v against_o that_o his_o supposition_n because_o many_o of_o they_o may_v be_v make_v also_o against_o his_o hypothesis_n of_o the_o heaven_n in_o general_a which_o i_o shall_v the_o rather_o omit_v because_o i_o do_v not_o find_v he_o have_v many_o follower_n in_o that_o supposition_n the_o generality_n of_o astronomer_n embrace_v rather_o the_o copernican_n system_n especial_o as_o it_o be_v refine_v and_o rectify_v by_o the_o ingenious_a kepler_n last_o i_o endeavour_v to_o trace_v the_o way_n of_o the_o comet_n from_o tycho_n table_n according_a to_o keplers_n hypothesis_n which_o be_v that_o the_o appearance_n of_o the_o motion_n of_o the_o comet_n be_v ascribable_a to_o two_o cause_n namely_o the_o motion_n of_o the_o earth_n about_o the_o sun_n in_o its_o annual_a orbit_n and_o the_o motion_n of_o the_o comet_n in_o a_o straight_a line_n not_o accelerate_a according_a to_o the_o proportion_n of_o the_o increase_n of_o tangent_n but_o upon_o supposition_n that_o it_o move_v equal_a space_n in_o equal_a time_n for_o i_o can_v imagine_v what_o reason_n he_o have_v to_o suppose_v its_o motion_n to_o be_v accelerate_a and_o much_o less_o why_o he_o shall_v assert_v it_o to_o be_v according_a to_o the_o proportion_n of_o tangent_n which_o in_o a_o little_a time_n must_v necessary_o come_v to_o move_v infinite_o swift_a than_o which_o nothing_o be_v more_o hard_a to_o be_v grant_v and_o i_o find_v it_o after_o many_o trial_n and_o essay_n to_o fall_v in_o a_o straight_a line_n incline_v to_o the_o plain_a of_o the_o ecliptic_a by_o anangle_n of_o 47._o 40._o and_o cut_v it_o in_o 9_o degree_n of_o scorpio_n if_o compute_v out_o of_o the_o sun_n and_o move_v fast_o by_o half_a than_o the_o earth_n in_o its_o orb_n and_o this_o to_o so_o great_a a_o exactness_n to_o answer_v all_o the_o observation_n of_o tycho_n that_o from_o a_o very_a large_a scheme_n which_o i_o draw_v of_o it_o on_o a_o plain_a i_o can_v never_o find_v many_o minute_n difference_n so_o that_o i_o conclude_v that_o to_o be_v the_o most_o likely_a hypothesis_n for_o that_o comet_n it_o seem_v to_o solve_v all_o the_o several_a phaenomena_n of_o the_o motion_n and_o magnitude_n of_o the_o comet_n with_o the_o least_o imaginable_a difficulty_n and_o to_o be_v most_o agreeable_a with_o my_o physical_a notion_n of_o comet_n for_o first_o it_o only_o suppose_v a_o solid_a body_n move_v in_o a_o fluid_fw-la with_o a_o almost_o direct_a motion_n i_o say_v almost_o direct_a because_o for_o some_o physical_a reason_n as_o i_o have_v say_v before_o i_o imagine_v it_o not_o exact_o straight_o but_o inflect_v a_o little_a towards_o the_o curvity_n of_o a_o circle_n which_o i_o shall_v present_o endeavour_v to_o explain_v far_o in_o this_o comet_n next_o it_o suppose_v that_o body_n to_o move_v in_o that_o line_n almost_o equal_a space_n in_o equal_a time_n i_o say_v almost_o equal_a because_o some_o of_o those_o equal_a space_n may_v be_v increase_v by_o a_o accelerate_a cause_n or_o principle_n such_o as_o that_o of_o a_o gravitation_n towards_o the_o body_n of_o the_o sun_n place_v in_o the_o centre_n of_o its_o vortice_fw-la or_o system_fw-la when_o the_o motion_n of_o the_o comet_n carry_v it_o towards_o the_o sun_n and_o may_v be_v diminish_v from_o other_o impede_a cause_n such_o as_o the_o impediment_n of_o the_o fluid_a medium_n through_o which_o it_o pass_v and_o the_o attraction_n of_o the_o sun_n operate_a on_o it_o when_o its_o motion_n carry_v it_o far_o and_o far_o off_o from_o it_o beside_o it_o be_v not_o unlikely_a but_o that_o the_o attraction_n of_o the_o earth_n or_o some_o of_o the_o other_o planet_n may_v have_v some_o kind_n of_o influence_n on_o it_o especial_o when_o its_o line_n of_o direction_n do_v somewhat_o near_o approach_v those_o attractive_a point_n but_o the_o deflection_n from_o a_o straight_a line_n be_v always_o so_o much_o the_o less_o by_o how_o much_o the_o swift_a the_o body_n be_v move_v and_o by_o how_o much_o the_o far_o off_o its_o line_n of_o trajection_n be_v perpendicular_o distant_a from_o those_o attract_v body_n according_a to_o this_o supposition_n of_o i_o i_o have_v endeavour_v to_o make_v out_o all_o the_o appearance_n of_o this_o last_o comet_n take_v notice_n of_o in_o the_o best_a observation_n i_o have_v yet_o meet_v with_o among_o which_o i_o find_v no_o one_o of_o the_o parallax_n satisfactory_a as_o in_o the_o ten_o figure_n let_v saint_n represent_v the_o sun_n orb_n the_o orb_n of_o the_o earth_n acdef_n a_o bend_a or_o curve_v line_n in_o which_o the_o comet_n be_v suppose_v to_o move_v the_o comet_n then_o come_v into_o the_o sphere_n of_o the_o attractive_a power_n of_o the_o sun_n by_o the_o straight_a
the_o centre_n of_o the_o shine_a body_n next_o that_o a_o firmament_n which_o divide_v between_o the_o water_n or_o the_o fluid_n of_o the_o one_o and_o the_o fluid_n of_o another_o part_n of_o the_o world_n and_o in_o the_o three_o place_n the_o collection_n of_o particular_a fluid_n to_o one_o centre_n as_o the_o centre_n of_o the_o earth_n and_o last_o out_o of_o that_o collection_n of_o fluid_n appear_v the_o dry_a and_o solid_a land_n so_o i_o conceive_v the_o most_o proper_a way_n of_o speculate_v on_o these_o great_a production_n of_o the_o omnipotent_a creator_n may_v be_v to_o begin_v with_o the_o consideration_n of_o light_n or_o the_o motion_n of_o recess_n from_o the_o centre_n of_o a_o body_n next_o with_o the_o consideration_n of_o the_o cause_n of_o the_o separate_n of_o fluid_a from_o fluid_fw-la as_o aether_n from_o aether_n as_o i_o may_v so_o call_v differ_v aether_n because_o we_o have_v not_o yet_o distinct_a name_n in_o use_n and_o the_o reason_n of_o their_o conglobation_n the_o aether_n from_o the_o air_n the_o air_n from_o the_o water_n the_o water_n from_o quicksilver_n oil_n or_o other_o fluid_a three_o the_o cause_n of_o the_o conglobate_v property_n of_o each_o of_o these_o fluid_n when_o separate_v how_o they_o accept_v and_o embrace_v homogenea_n and_o reject_v or_o expel_v heterogenea_n and_o four_a how_o they_o condense_a and_o settle_v together_o and_o produce_v a_o solid_a body_n whence_o proceed_v the_o confirmation_n of_o attraction_n or_o gravitation_n etc._n etc._n but_o to_o digress_v no_o further_o but_o conclude_v this_o part_n of_o enquiry_n in_o short_a i_o suppose_v the_o nucleus_n or_o star_n of_o the_o comet_n may_v be_v much_o of_o the_o like_a nature_n with_o the_o central_a part_n of_o the_o earth_n moon_n mars_n jupiter_n saturn_n or_o other_o planet_n but_o much_o impair_v in_o its_o attractive_a or_o gravitating_a power_n next_o that_o the_o coma_n or_o hazy_a cloud_n about_o it_o may_v be_v of_o the_o nature_n of_o the_o atmosphere_n or_o air_n about_o the_o earth_n or_o the_o smoke_n or_o steam_n about_o a_o heat_a or_o burn_a body_n before_o they_o be_v quite_o kindle_v convert_v into_o flame_n or_o dissolve_v into_o the_o ambient_fw-la air._n three_o that_o the_o tail_n or_o blaze_n be_v much_o of_o the_o nature_n of_o the_o part_n of_o flame_n though_o with_o those_o difference_n i_o conceive_v that_o the_o part_n of_o these_o steam_n be_v not_o so_o close_o together_o as_o be_v those_o of_o smoke_n nor_o do_v the_o motion_n of_o they_o though_o much_o swift_a upward_o than_o that_o of_o our_o flame_n serve_v to_o make_v they_o appear_v a_o shine_a line_n but_o be_v at_o that_o distance_n they_o appear_v much_o slow_a to_o the_o eye_n and_o so_o discontinue_v the_o appearance_n whence_o every_o shine_a particle_n appear_v only_o a_o shine_a point_n though_o in_o the_o part_n of_o flame_n where_o notwithstanding_o the_o motion_n be_v much_o flower_n yet_o be_v near_o and_o so_o vary_v the_o position_n to_o the_o eye_n much_o quick_a each_o of_o the_o shine_a part_n make_v a_o appearance_n of_o a_o line_n of_o light_n and_o all_o of_o they_o pass_v pretty_a near_o together_o make_v the_o appearance_n of_o a_o continue_a fluid_a flame_n though_o that_o indeed_o be_v nothing_o but_o a_o great_a number_n of_o single_a parcel_n of_o the_o burn_a body_n raise_v up_o in_o the_o particle_n of_o smoke_n this_o will_v appear_v evident_a if_o we_o consider_v the_o appearance_n easy_o to_o be_v take_v notice_n of_o in_o light_n for_o it_o be_v obvious_a from_o multitude_n of_o experiment_n that_o any_o shine_a body_n as_o a_o candle_n or_o brand_n end_v be_v move_v very_o quick_a make_v the_o same_o impression_n on_o the_o eye_n that_o a_o line_n of_o light_n do_v stand_v still_o and_o as_o obvious_a also_o that_o any_o very_a light_a body_n encompass_v with_o a_o dark_a medium_n appear_v to_o the_o eye_n under_o a_o angle_n big_a than_o real_o it_o be_v and_o a_o dark_a body_n encompass_v with_o a_o light_a medium_n much_o less_o this_o any_o one_o may_v present_o find_v if_o he_o make_v a_o small_a hole_n through_o a_o thin_a plate_n of_o metal_n and_o hold_v it_o first_o between_o the_o light_n and_o the_o eye_n and_o so_o see_v the_o light_n appear_v through_o it_o and_o then_o place_v it_o so_o as_o there_o be_v nothing_o but_o darkness_n appear_v through_o the_o say_a hole_n for_o he_o will_v plain_o perceive_v that_o the_o same_o hole_n will_v appear_v much_o big_a in_o the_o former_a position_n than_o in_o the_o latter_a upon_o this_o account_n indeed_o each_o of_o the_o shine_a part_n of_o the_o comet_n seem_v to_o fill_v and_o occupy_v a_o much_o great_a space_n than_o real_o it_o do_v and_o so_o as_o it_o be_v observable_a in_o the_o milky_a way_n a_o great_a number_n of_o these_o small_a shine_a body_n though_o disperse_v at_o a_o pretty_a distance_n one_o from_o another_o yet_o by_o reason_n of_o the_o imperceptibleness_n of_o each_o of_o they_o they_o all_o seem_v to_o coalesce_v into_o a_o stream_n or_o blaze_n of_o light_n the_o brightness_n of_o which_o be_v yet_o far_o augment_v by_o a_o clear_a and_o unenlightened_a air_n and_o by_o such_o a_o part_n of_o the_o heaven_n wherein_o there_o appear_v few_o of_o the_o star_n whether_o they_o be_v great_a or_o lesser_a to_o the_o query_n of_o what_o magnitude_n the_o body_n coma_n and_o blaze_n of_o comet_n may_v be_v no_o answer_n can_v be_v give_v until_o another_o question_n be_v first_o answer_v and_o that_o be_v what_o be_v the_o place_n of_o comet_n and_o what_o be_v their_o distance_n from_o the_o earth_n it_o be_v the_o opinion_n of_o most_o modern_a writer_n before_o tycho_n brahe_n and_o kepler_n i_o know_v divers_a of_o the_o ancient_n think_v otherwise_o that_o comet_n be_v sublunary_a meteor_n draw_v up_o into_o the_o high_a region_n of_o the_o air_n and_o there_o set_v on_o fire_n and_o so_o continue_v burn_v till_o the_o meteor_n be_v consume_v and_o as_o the_o matter_n increase_v or_o waste_v so_o do_v the_o appearance_n of_o the_o comet_n but_o this_o noble_a dane_n and_o several_a other_o about_o that_o time_n find_v by_o accurate_a observation_n make_v that_o its_o parallax_n be_v less_o than_o that_o of_o the_o moon_n and_o consequent_o that_o it_o be_v far_o distant_a from_o the_o earth_n that_o it_o must_v be_v a_o body_n of_o another_o magnitude_n and_o nature_n than_o most_o before_o that_o time_n have_v imagine_v and_o therefore_o that_o it_o ought_v to_o be_v otherwise_o think_v of_o than_o the_o generality_n of_o mankind_n believe_v concern_v it_o many_o have_v be_v the_o attempt_n of_o former_a writer_n concern_v they_o to_o find_v out_o their_o parallax_n and_o whether_o from_o their_o unaccurate_a instrument_n or_o from_o their_o less_o skill_n and_o diligence_n in_o use_v they_o or_o from_o a_o imagination_n of_o the_o solidity_n and_o impenetrability_n of_o the_o celestial_a orb_n or_o from_o error_n in_o their_o calculation_n or_o from_o compare_v observation_n make_v at_o distant_a place_n one_o or_o both_o whereof_o be_v unaccurate_a or_o from_o a_o prepossession_n of_o tradition_n or_o common_a fame_n or_o from_o what_o other_o cause_n soever_o it_o be_v be_v uncertain_a but_o it_o be_v general_o conclude_v by_o they_o that_o all_o comet_n be_v sublunary_a meteor_n and_o there_o be_v not_o even_o at_o this_o day_n want_v some_o of_o the_o same_o opinion_n though_o for_o what_o reason_n i_o know_v not_o it_o will_v be_v hard_a to_o convince_v some_o of_o these_o that_o the_o opinion_n they_o have_v hitherto_o receive_v for_o good_a be_v not_o so_o because_o they_o will_v hardly_o give_v themselves_o the_o trouble_n of_o examine_v strict_o into_o the_o matter_n and_o to_o understand_v the_o nature_n of_o parallax_n and_o how_o significant_a they_o be_v in_o determine_v the_o distance_n of_o body_n from_o the_o surface_n of_o the_o earth_n to_o certain_a degree_n thereof_o beyond_o which_o by_o reason_n of_o the_o imperfection_n in_o instrument_n and_o observation_n and_o the_o exceed_a niceness_n and_o curiosity_n necessary_a they_o signify_v very_o little_a it_o be_v not_o my_o present_a design_n to_o explain_v what_o parallax_n be_v that_o i_o will_v suppose_v my_o reader_n to_o understand_v otherwise_o there_o can_v be_v no_o reason_n show_v he_o to_o convince_v he_o that_o it_o be_v possible_a to_o prove_v that_o this_o or_o that_o comet_n be_v not_o near_a than_o so_o many_o semidiameter_n of_o the_o earth_n nor_o far_o off_o than_o so_o many_o there_o be_v then_o two_o way_n by_o which_o we_o may_v come_v to_o some_o certainty_n of_o what_o distance_n a_o comet_n be_v and_o those_o be_v first_o the_o parallax_n of_o its_o diurnal_a motion_n or_o its_o parallax_n cause_v by_o the_o diurnal_a motion_n of_o the_o earth_n and_o
be_v take_v up_o into_o it_o and_o keep_v suspend_v therein_o though_o the_o part_n of_o the_o gold_n be_v fifteen_o time_n heavy_a than_o the_o part_n of_o the_o aqua_fw-la regis_fw-la so_o pit-coal_n though_o very_o heavy_a be_v yet_o take_v up_o into_o the_o air_n and_o keep_v suspend_v therein_o though_o it_o will_v be_v find_v to_o be_v some_o thousand_o of_o time_n more_o ponderous_a than_o the_o menstruum_fw-la of_o the_o air_n that_o keep_v it_o suspend_v many_o reason_n i_o can_v produce_v to_o show_v the_o great_a power_n of_o the_o aether_n and_o the_o universality_n of_o its_o activity_n almost_o in_o all_o sensible_a motion_n but_o reserve_v they_o for_o another_o discourse_n hereafter_o i_o shall_v at_o present_a only_o mention_v those_o supposition_n which_o seem_v to_o have_v the_o great_a difficulty_n in_o this_o theory_n viz._n how_o the_o dissolution_n of_o the_o part_n of_o the_o star_n by_o the_o encompass_v aether_n shall_v cause_v light_n and_o second_o how_o it_o shall_v cause_v a_o actual_a levitation_n of_o the_o dissolve_v particle_n upward_o for_o the_o explication_n of_o these_o two_o difficulty_n i_o must_v at_o present_a crave_v favour_n to_o explain_v they_o by_o example_n take_v from_o operation_n of_o nature_n in_o the_o atmosphere_n wherein_o we_o live_v very_o similar_v and_o analogous_a to_o they_o first_o for_o the_o production_n of_o light_n we_o find_v that_o the_o air_n encompass_v the_o steam_n of_o body_n prepare_v by_o heat_n or_o otherwise_o and_o make_v fit_a for_o dissolution_n do_v so_o operate_v upon_o they_o as_o to_o make_v they_o fly_v and_o part_v asunder_o with_o a_o very_a impetuous_a motion_n insomuch_o that_o the_o small_a particle_n or_o atom_n of_o the_o dissolve_a body_n do_v not_o only_o leave_v one_o another_o but_o depart_v and_o dart_v out_o with_o so_o great_a a_o impetuosity_n as_o to_o drive_v off_o all_o the_o encompass_v air_n from_o their_o centre_n from_o whence_o they_o fly_v and_o this_o i_o 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nature_n in_o other_o operation_n and_o though_o the_o supposition_n even_o of_o the_o aether_n may_v seem_v to_o be_v a_o chimaera_n and_o groundless_a yet_o have_v i_o now_o time_n i_o can_v by_o many_o very_a sensible_a and_o undeniable_a experiment_n prove_v the_o existence_n and_o reality_n thereof_o and_o that_o it_o do_v actual_o produce_v not_o only_o as_o sensible_a effect_n as_o these_o i_o have_v name_v but_o very_o much_o the_o same_o and_o many_o other_o much_o more_o cosiderable_a which_o by_o philosopher_n have_v hitherto_o be_v ascribe_v to_o quite_o different_a cause_n have_v i_o be_v able_a to_o have_v make_v some_o other_o observation_n which_o i_o design_v if_o i_o have_v have_v the_o opportunity_n of_o see_v it_o some_o of_o the_o succeed_a night_n i_o shall_v have_v hope_v to_o have_v explain_v several_a other_o difficulty_n concern_v the_o nature_n of_o the_o body_n and_o blaze_n of_o comet_n but_o be_v therein_o prevent_v i_o must_v leave_v they_o till_o i_o can_v make_v some_o further_a observation_n on_o some_o comet_n that_o may_v hereafter_o appear_v in_o the_o mean_a time_n that_o what_o i_o have_v discourse_v concern_v the_o light_n of_o comet_n may_v not_o seem_v so_o altogether_o paradoxical_a and_o unintelligible_a as_o some_o may_v imagine_v i_o have_v here_o add_v a_o account_n of_o some_o trial_n and_o observation_n make_v on_o shine_a substance_n of_o nature_n exceed_o differ_v from_o those_o that_o be_v common_o to_o be_v meet_v withal_o and_o this_o i_o the_o rather_o do_v not_o only_o because_o it_o afford_v a_o instance_n of_o shine_v where_o there_o be_v no_o air_n but_o that_o hereby_o i_o may_v enlarge_v the_o limit_n of_o their_o imagination_n who_o shall_v consider_v of_o this_o subject_n for_o nothing_o be_v more_o apt_a to_o misguide_v our_o reason_n than_o a_o narrow_a and_o limit_a knowledge_n of_o cause_n we_o be_v not_o to_o conclude_v the_o body_n of_o a_o comet_n a_o sulphureous_a vapour_n exhale_v from_o the_o earth_n and_o kindle_v above_o because_o here_o be_v such_o vapour_n observe_v and_o such_o effect_n produce_v nor_o a_o collection_n of_o sun_n beam_n make_v by_o a_o lentiformed_a vapour_n after_o the_o manner_n of_o a_o burning-glass_n as_o some_o eminent_a writer_n have_v late_o do_v because_o some_o such_o appearance_n may_v be_v artificial_o produce_v in_o a_o smoky_a or_o thicken_a air_n since_o if_o we_o diligent_o inquire_v we_o may_v find_v that_o light_n which_o be_v the_o most_o sensible_a quality_n of_o comet_n that_o affect_v our_o sense_n may_v be_v and_o real_o be_v produce_v by_o very_a many_o and_o those_o very_a differ_a way_n in_o nitre_n and_o sulphur_n kindle_v each_o other_o by_o heat_n we_o have_v one_o way_n in_o a_o body_n burn_v in_o the_o air_n a_o second_o in_o a_o heat_a iron_n or_o glass_n a_o three_o in_o a_o piece_n of_o iron_n hammer_v till_o red_a hot_a a_o four_o in_o rot_a wood_n and_o decay_a fish_n a_o five_o in_o glow-worm_n scolopondras_n and_o other_o live_a worm_n and_o in_o the_o sweat_n and_o excrement_n of_o other_o live_a creature_n a_o six_o in_o a_o diamond_n rub_v a_o seven_o in_o dew_n ignes_fw-la fatui_fw-la etc._n etc._n a_o eight_o in_o sea-water_n a_o nine_o in_o the_o bononian_n stone_n and_o in_o the_o phosphorus_n baldwini_n which_o i_o take_v to_o be_v much_o of_o the_o same_o nature_n a_o ten_o in_o the_o phosphorus_n of_o mr._n kraft_n a_o eleven_o and_o possible_o whole_o differ_v from_o all_o these_o may_v be_v the_o light_n of_o the_o sun_n a_o twelve_o and_o that_o of_o the_o star_n may_v differ_v from_o that_o of_o sun_n and_o the_o comet_n may_v be_v differ_v from_o all_o the_o rest_n whether_o they_o be_v so_o or_o not_o the_o be_v acquaint_v with_o the_o several_a propriety_n of_o they_o will_v the_o better_o enable_v one_o to_o judge_n of_o what_o be_v pertinent_a to_o be_v observe_v in_o comet_n in_o order_n to_o find_v out_o which_o be_v concern_v the_o phaenomena_n of_o most_o of_o these_o shine_a body_n be_v very_o common_a and_o obvious_a and_o therefore_o needless_a to_o be_v add_v but_o that_o of_o the_o bononian_n stone_n prepare_v and_o that_o of_o the_o phosphorus_n baldwini_n late_o discover_v by_o mr._n baldwine_n be_v rare_a and_o hard_a to_o be_v get_v and_o the_o effect_n of_o they_o be_v whole_o differ_v from_o all_o the_o way_n i_o have_v yet_o meet_v with_o and_o will_v therefore_o prove_v experimenta_fw-la crucis_fw-la high_o instructive_a in_o the_o theory_n of_o light_n of_o which_o more_o hereafter_o as_o for_o the_o phosphoros_n fulgurans_fw-la of_o mr._n kraft_n more_o scarce_o and_o rare_a than_o the_o other_o it_o be_v whole_o differ_v from_o any_o of_o the_o rest_n and_o very_o strange_a and_o surprise_a at_o least_o it_o appear_v so_o to_o i_o who_o have_v the_o good_a fortune_n to_o be_v present_a at_o a_o good_a part_n of_o
since_o the_o appearance_n may_v be_v solve_v by_o circle_n of_o any_o bigness_n prove_v by_o the_o eight_o figure_n 29._o allow_v inequality_n of_o motion_n or_o more_o compound_n curve_v line_n nothing_o can_v be_v determine_v the_o circular_a orb_n it_o seem_v the_o most_o probable_a solve_v kepler_n acceleration_n according_a to_o the_o increase_n of_o a_o line_n of_o tangent_n 30._o a_o gravitation_n towards_o the_o sun_n make_v out_o the_o motion_n of_o the_o comet_n and_o planet_n and_o of_o the_o blaze_n the_o blaze_n explain_v by_o experiment_n of_o ♂_o dissolve_v in_o oil_n of_o virt._n 31._o this_o experiment_n and_o hypothesis_n far_o explain_v and_o apply_v to_o explain_v the_o blaze_n which_o be_v from_o thence_o bend_v bright_a on_o one_o side_n than_o the_o other_o not_o direct_v from_o the_o sun_n 32._o cometical_a body_n and_o motion_n as_o old_a as_o the_o world_n yet_o waste_v in_o the_o aether_n explain_v by_o fire_n dissolution_n by_o menstruum_n 33._o thence_o the_o propriety_n of_o comet_n conjecture_v and_o the_o sum_n of_o the_o forego_n discourse_n repeat_v be_v the_o end_n of_o a_o lecture_n recourse_n to_o tycho_n brahe_n observation_n 34._o for_o make_v out_o the_o comet_n orb._n his_o suppose_v its_o motion_n unequal_a without_o reason_n a_o shift_n mr._n horrox_n his_o hypothesis_n in_o the_o nine_o figure_n a_o product_n of_o chance_n 35._o a_o discourse_n on_o it_o and_o some_o objection_n against_o tycho_n 36._o kepler_n hypothesis_n examine_v by_o these_o observation_n of_o tycho_n find_v the_o most_o likely_a but_o with_o some_o alteration_n line_n of_o trajection_n bend_v a_o little_a motion_n accelerate_a towards_o the_o sun_n retard_v from_o it_o 37._o the_o swift_a and_o further_o off_o the_o comet_n from_o the_o sun_n the_o less_o the_o bend_n explain_v by_o the_o ten_o figure_n 38._o the_o way_n of_o inquire_a parallax_n by_o telescope_n 39_o further_o explain_v a_o second_o way_n by_o two_o observer_n in_o distant_a place_n propound_v the_o three_o way_n of_o sir_n chr._n wren_n his_o majesty_n surveyor-general_n 40._o set_a down_o and_o demonstrate_v by_o a_o geometrical_a problem_n 41._o how_o exact_o all_o those_o observation_n he_o have_v be_v make_v out_o by_o it_o together_o with_o his_o own_o scheme_n both_o which_o i_o have_v in_o the_o begin_n of_o feb._n 1664-5_a 42._o some_o other_o paper_n about_o comet_n add_v be_v reflection_n on_o mr._n descartes_n and_o kepler_n hypothesis_n from_o particular_a tracing_n of_o the_o comet_n of_o 1664._o and_o 1665._o a_o scheme_n of_o the_o late_a observation_n of_o that_o of_o 1664._o add_v and_o some_o reflection_n be_v all_o the_o paper_n can_v be_v find_v about_o those_o comet_n 43_o 44._o animadversion_n on_o this_o of_o april_n last_o why_o the_o former_a conjecture_n be_v adhere_v to_o concern_v the_o light_n of_o comet_n 45._o several_a sort_n of_o shine_a body_n enumerate_v 46_o to_o which_o the_o light_n of_o the_o comet_n seem_v to_o have_v most_o affinity_n and_o how_o produce_v 47._o further_o describe_v and_o explain_v 48._o the_o reason_n of_o its_o parabolic_a figure_n demonstrate_v from_o the_o propriety_n of_o motion_n from_o or_o towards_o a_o gravitating_a body_n as_o the_o sun_n 49._o concern_v the_o waste_n and_o last_v of_o the_o cometical_a body_n the_o bigness_n and_o nature_n of_o the_o particle_n that_o compose_v the_o blaze_n 50._o some_o difficulty_n in_o this_o supposition_n concern_v the_o action_n of_o the_o aether_n in_o levitation_n and_o ascent_n dissolution_n shine_v etc._n etc._n clear_v and_o explain_v by_o experiment_n 51_o 52_o 53._o but_o will_v have_v be_v further_o examine_v by_o observation_n if_o there_o have_v be_v opportunity_n 54._o that_o these_o assertion_n about_o the_o light_n of_o comet_n may_v not_o seem_v too_o paradoxical_a some_o further_a consideration_n and_o observation_n about_o light_n be_v add_v and_o some_o new_a way_n propound_v 55_o 56._o mr._n boyle_n memorial_n concern_v a_o phosphoros_n write_v for_o his_o own_o use_n insert_v in_o which_o he_o first_o name_v the_o author_n of_o it_o and_o describe_v his_o apparatus_fw-la 57_o 58._o then_o the_o observables_n 1._o two_o spoonful_n of_o matter_n enlighten_v a_o large_a glass_n sphere_n 2._o a_o little_a enlighten_v a_o large_a cylinder_n 3._o liquor_n shake_v have_v a_o smoke_n and_o flash_v 4._o a_o dry_a substance_n affirm_v to_o have_v continue_v shine_v 2_o year_n flash_v 59_o 5._o some_o dust_n of_o this_o on_o a_o carpet_n twinkle_v like_o star_n write_v on_o paper_n with_o it_o shine_v and_o smell_v of_o sulphur_n and_o onion_n 60._o 7._o the_o hand_n on_o which_o it_o be_v rub_v shine_v but_o feel_v no_o heat_n 61._o it_o fire_v gunpowder_n first_o warm_v 62._o and_o white_a paper_n hold_v over_o coal_n other_o trial_n propound_v but_o refuse_v 63._o some_o experiment_n make_v on_o the_o phosphoros_n baldwini_n in_o vacuo_fw-la and_o in_o the_o open_a air_n 64._o preserve_v in_o vacuo_fw-la but_o destroy_v in_o air._n 65_o 66._o monsieur_n gallet_n letter_n to_o monsieur_n cassini_n acquaint_v he_o with_o his_o apparatus_fw-la for_o observe_v ☿_o in_o ☉_o 67_o 68_o his_o observation_n of_o sour_a spot_n in_o ☉_o 69._o the_o particular_n observe_v 70._o 71_o 72._o monsieur_n cassini_n reflection_n on_o these_o observation_n 73_o 74._o mr._n hally_n letter_n to_o sir_n ionas_n moor_n contain_v a_o account_n of_o his_o observation_n of_o ☿_o sub_fw-la sole_a three_o southern_a star_n the_o two_o nubeculae_fw-la etc._n etc._n 75_o 76_o 77._o mr._n cassini_n far_a discovery_n about_o the_o diurnal_a motion_n and_o several_a new_a appearance_n in_o ♃_o 78_o 79_o 80._o a_o second_o discourse_v call_v microscopium_n or_o some_o new_a discovery_n with_o microscope_n in_o a_o letter_n of_o mr._n leeuwenhoeck_n 81._o 82._o a_o confirmation_n of_o some_o of_o they_o by_o observation_n here_o 83._o mr._n leeuwenhoeck_n second_o letter_n contain_v observation_n of_o the_o globule_n of_o blood_n milk_n phlegm_n gum_n first_o dissolve_v then_o precipitate_v out_o of_o the_o spirit_n of_o wine_n eel_n a_o thousand_o time_n thin_a than_o a_o hair_n 84_o 85_o 86_o 87_o 88_o 89._o the_o way_n how_o these_o discovery_n be_v make_v here_o 1._o by_o hold_v the_o liquor_n in_o small_a pipe_n how_o fill_v how_o make_v the_o lamp_n pipe_n oil_n manner_n material_n for_o make_v they_o describe_v 89_o 90._o muscovy-glass_n use_v instead_o of_o these_o pipe_n and_o how_o the_o microscope_n be_v fit_v for_o this_o purpose_n 91._o what_o light_a convenient_a surface_v of_o body_n not_o perfect_o fluid_v apt_a to_o delude_v a_o observer_n 92._o plate_n remove_v that_o delude_a cause_n and_o what_o far_a use_n of_o they_o 93._o how_o to_o find_v the_o figure_n and_o texture_n of_o animal_n and_o vegetable_a part_n instance_n in_o a_o ligament_n of_o beef_n 94._o the_o figure_n of_o muscle_n hint_v and_o a_o instrument_n stretch_v they_o before_o the_o glass_n describe_v 95._o a_o description_n of_o the_o microscope_n use_v 1._o of_o the_o single_a microscope_n and_o its_o advantage_n and_o difficulty_n 96._o another_o sort_n more_o easy_a describe_v and_o the_o way_n how_o to_o make_v and_o use_v it_o explain_v 97._o cause_n that_o vary_v the_o distance_n of_o object_n from_o the_o globule_n the_o use_n of_o selenites_n and_o looking-glass-plate_n for_o hold_v the_o liquor_n a_o microscope_n of_o one_o single_a refraction_n 98._o the_o only_a inconvenience_n of_o they_o hint_v how_o prevent_v by_o double_a microscope_n where_o these_o be_v make_v 99_o the_o double_a microscope_n and_o its_o part_n use_n and_o advantage_n describe_v 100_o the_o benefit_n of_o a_o dark_a room_n and_o appropriate_v light_n and_o a_o digression_n in_o answer_n to_o p._n cherubin_n accusation_n 101._o some_o observation_n make_v with_o this_o microscope_n hint_v animalcules_n in_o the_o steep_v of_o other_o grain_n beside_o pepper_n their_o smallness_n estimate_v and_o compare_v to_o a_o whale_n muscular_a fabric_n hint_v milk_n blood_n fat_a sugar_n alum_n etc._n etc._n view_v 102_o 103._o mr._n young_n letter_n of_o one_o who_o try_v to_o cure_v a_o colic_n by_o leaden_a pill_n slip_v one_o into_o his_o lung_n grievous_a symptom_n ensue_v 105._o help_v of_o skilful_a physician_n in_o vain_a attempt_v and_o particular_o of_o dr._n mayow_o of_o suspend_v with_o the_o head_n downward_o though_o in_o the_o interim_n he_o marry_v and_o have_v child_n yet_o it_o kill_v he_o 106_o 107._o his_o body_n diffect_v and_o remarkable_n take_v notice_n of_o and_o their_o cause_n explain_v by_o mr._n young_a from_o 107._o to_o 112._o cometa_fw-la or_o remark_n about_o comet_n on_o saturday_n morning_n april_n 21._o 1677._o i_o first_o see_v the_o comet_n of_o which_o i_o have_v be_v advertise_v the_o day_n before_o it_o appear_v in_o the_o sign_n taurus_n between_o the_o base_a of_o the_o triangle_n and_o the_o unformed_a star_n in_o the_o
every_o piece_n of_o it_o though_o infinite_o divide_v the_o same_o propriety_n it_o have_v itself_o this_o magnetical_a virtue_n i_o say_v have_v such_o a_o relation_n and_o be_v force_v thus_o to_o vary_v it_o be_v very_o probable_a that_o the_o internal_a part_n to_o which_o it_o have_v a_o respect_n have_v a_o variation_n likewise_o and_o consequent_o that_o these_o internal_a part_n which_o be_v suppose_v general_o very_o dense_a compact_a and_o very_o close_o and_o solid_o unite_v may_v be_v notwithstanding_o more_o loose_a and_o ununited_a and_o movable_a from_o certain_a cause_n to_o proceed_v therefore_o i_o say_v that_o it_o seem_v very_o probable_a to_o i_o that_o the_o body_n of_o comet_n may_v be_v of_o the_o same_o nature_n and_o constitution_n with_o that_o of_o the_o internal_a part_n of_o the_o earth_n that_o these_o part_n may_v by_o the_o help_n of_o the_o aether_n be_v so_o agitate_a and_o blend_a together_o as_o to_o make_v they_o work_v upon_o and_o dissolve_v each_o other_o in_o the_o same_o manner_n as_o we_o have_v often_o have_v example_n of_o some_o of_o the_o part_n of_o the_o earth_n a_o late_a instance_n of_o which_o be_v at_o mongibel_n or_o aetna_n in_o sicily_n where_o the_o fire_n continue_v for_o a_o long_a time_n and_o produce_v very_o considerable_a effect_n that_o this_o internal_a agitation_n may_v confound_v the_o gravitating_a principle_n and_o so_o leave_v the_o part_n in_o a_o great_a freedom_n to_o be_v dissolve_v by_o the_o encompass_v aether_n which_o be_v the_o agent_n that_o set_v the_o other_o two_o at_o work_n to_o destroy_v each_o other_o that_o it_o may_v at_o length_n prey_n upon_o both_o and_o dissolve_v they_o both_o into_o itself_o and_o consequent_o not_o only_o the_o part_n thus_o dissolve_v be_v elevate_v to_o a_o great_a distance_n from_o the_o centre_n of_o the_o star_n or_o nucleus_n or_o the_o superficies_n of_o it_o who_o gravitating_a or_o attractive_a principle_n be_v much_o destroy_v the_o coma_n be_v in_o this_o comet_n four_o or_o five_o diameter_n of_o the_o star_n or_o nucleus_n but_o have_v give_v those_o part_n leave_v thus_o far_o to_o ramble_v the_o gravitating_a principle_n of_o another_o body_n more_o potent_a act_n upon_o it_o and_o make_v those_o part_n seem_v to_o recede_v from_o the_o centre_n thereof_o though_o real_o they_o be_v but_o as_o it_o be_v leave_v behind_o the_o body_n of_o the_o star_n which_o be_v more_o powerful_o attract_v than_o the_o minute_a steam_a part_n for_o i_o suppose_v the_o gravitating_a power_n of_o the_o sun_n in_o the_o centre_n of_o this_o part_n of_o the_o heaven_n in_o which_o we_o be_v have_v a_o attractive_a power_n upon_o all_o the_o body_n of_o the_o planet_n and_o of_o the_o earth_n that_o move_v about_o it_o and_o that_o each_o of_o those_o again_o have_v a_o respect_n answerable_a whereby_o they_o may_v be_v say_v to_o attract_v the_o sun_n in_o the_o same_o manner_n as_o the_o loadstone_n have_v to_o iron_n and_o the_o iron_n have_v to_o the_o loadstone_n i_o conceive_v also_o that_o this_o attractive_a virtue_n may_v act_v likewise_o upon_o several_a other_o body_n that_o come_v within_o the_o centre_n of_o its_o sphere_n of_o activity_n though_o it_o be_v not_o improbable_a also_o but_o that_o as_o on_o some_o body_n it_o may_v have_v no_o effect_n at_o all_o no_o more_o than_o the_o loadstone_n which_o act_v on_o iron_n have_v upon_o a_o bar_n of_o tin_n lead_v glass_n wood_n etc._n etc._n so_o on_o other_o body_n it_o may_v have_v a_o clean_a contrary_a effect_n that_o be_v of_o protrusion_n thrust_v off_o or_o drive_v away_o as_o we_o find_v one_o pole_n of_o the_o magnet_n do_v the_o end_n of_o a_o needle_n touch_v on_o the_o opposite_a part_n whence_o it_o be_v i_o conceive_v that_o the_o part_n of_o the_o body_n of_o this_o comet_n be_v confound_v or_o jumble_v as_o it_o be_v together_o and_o so_o the_o gravitating_a principle_n destroy_v become_v of_o other_o nature_n than_o they_o be_v before_o and_o so_o the_o body_n may_v cease_v to_o maintain_v its_o place_n in_o the_o universe_n where_o first_o it_o be_v place_v whence_o instead_o of_o continue_v to_o move_v round_o some_o central_a body_n whether_o sun_n or_o planet_n as_o it_o do_v whilst_o it_o maintain_v itself_o entire_a and_o so_o have_v its_o magnetical_a quality_n as_o i_o may_v so_o call_v it_o unconfound_v it_o now_o leave_v that_o circular_a way_n and_o by_o its_o motion_n which_o always_o tend_v to_o a_o straight_a line_n and_o will_v be_v so_o be_v it_o not_o bend_v into_o a_o curve_v by_o the_o attractive_a virtue_n of_o the_o central_a body_n it_o fly_v away_o from_o its_o former_a centre_n by_o the_o tangent_fw-la line_n to_o the_o last_o place_n where_o it_o be_v before_o this_o confusion_n be_v cause_v in_o the_o body_n of_o it_o in_o this_o line_n it_o be_v probable_a it_o pass_v from_o one_o part_n of_o the_o heaven_n to_o another_o and_o so_o pass_v through_o the_o sphere_n of_o the_o activity_n of_o multitude_n of_o central_a body_n in_o the_o pass_n through_o which_o sphere_n it_o be_v not_o improbable_a that_o those_o part_n which_o by_o their_o dissolution_n be_v make_v of_o a_o nature_n differ_v from_o the_o body_n in_o the_o centre_n be_v rather_o expel_v from_o than_o attract_v towards_o it_o and_o so_o be_v by_o this_o dissolution_n rarify_v and_o loosen_v from_o the_o middle_n and_o by_o their_o act_n upon_o one_o another_o and_o dissolution_n of_o the_o aether_n make_v of_o another_o nature_n after_o they_o have_v every_o way_n disperse_v themselves_o to_o a_o considerable_a distance_n from_o their_o proper_a body_n be_v convert_v and_o drive_v in_o a_o way_n almost_o opposite_a to_o that_o expelling_a body_n and_o so_o continue_v to_o be_v drive_v away_o to_o such_o a_o vast_a distance_n as_o to_o make_v out_o that_o prodigious_a length_n of_o the_o tail_n or_o blaze_n of_o some_o comet_n such_o as_o be_v that_o of_o 1618._o which_o as_o kepler_n report_v be_v extend_v to_o 70_o degree_n from_o the_o body_n or_o head_n of_o it_o till_o at_o last_o they_o be_v dissolve_v also_o and_o commix_v with_o the_o aether_n within_o they_o so_o that_o though_o i_o suppose_v the_o attractive_a power_n of_o the_o sun_n or_o other_o central_a body_n may_v draw_v the_o body_n towards_o it_o and_o so_o bend_v the_o motion_n of_o the_o comet_n from_o the_o straight_a line_n in_o which_o it_o tend_v into_o a_o kind_n of_o curve_v who_o concave_a part_n be_v towards_o the_o sun_n by_o reason_n that_o there_o be_v some_o central_a part_n of_o it_o which_o be_v not_o yet_o destroy_v and_o so_o retain_v somewhat_o of_o its_o gravitating_a principle_n yet_o i_o conceive_v that_o all_o those_o part_n of_o the_o comet_n which_o be_v thus_o wrought_v upon_o by_o the_o other_o and_o change_v into_o another_o state_n and_o be_v very_o much_o rarify_v and_o produce_v light_a be_v of_o a_o clean_a contrary_a nature_n and_o recede_v from_o the_o centre_n of_o the_o sun_n much_o after_o the_o same_o manner_n as_o we_o find_v any_o combustible_a body_n with_o we_o as_o coal_n etc._n etc._n where_o we_o find_v that_o the_o body_n of_o the_o coal_n before_o it_o be_v resolve_v into_o smoke_n be_v a_o very_a dense_n and_o very_o heavy_a body_n and_o tend_v to_o the_o centre_n of_o the_o earth_n but_o the_o part_n thereof_o agitate_a by_o the_o air_n and_o aether_n into_o steam_n and_o smoke_n and_o those_o yet_o far_a dissolve_v into_o flame_n do_v tend_v upward_o and_o from_o the_o centre_n of_o the_o earth_n now_o though_o one_o cause_n of_o the_o recess_n of_o flame_n from_o the_o centre_n of_o the_o earth_n be_v the_o gravity_n of_o the_o ambient_fw-la air._n yet_o it_o be_v not_o impossible_a but_o that_o there_o may_v be_v somewhat_o also_o of_o positive_a levity_n conjoin_v therewith_o most_o certain_a it_o be_v that_o there_o must_v be_v a_o tendency_n of_o recede_v as_o well_o as_o a_o tendency_n of_o approach_v the_o centre_n of_o the_o earth_n and_o other_o attract_v body_n and_o there_o may_v be_v much_o say_v for_o the_o supposition_n that_o the_o recess_n of_o the_o pure_a aether_n from_o the_o centre_n be_v the_o cause_n of_o the_o motion_n of_o the_o grosser_n aether_n and_o of_o all_o other_o body_n towards_o it_o though_o there_o be_v also_o very_o considerable_a argument_n against_o it_o but_o this_o discourse_n be_v not_o my_o present_a business_n though_o it_o may_v hereafter_o be_v the_o subject_n of_o a_o lecture_n in_o this_o place_n for_o upon_o it_o do_v depend_v some_o of_o the_o great_a operation_n in_o the_o universe_n and_o as_o in_o the_o history_n of_o the_o creation_n we_o have_v a_o account_n of_o the_o production_n of_o light_n immediate_o after_o the_o make_n of_o matter_n which_o be_v a_o motion_n of_o recess_n from_o
side_n the_o nucleus_n or_o ball_n in_o the_o middle_n of_o the_o head_n which_o i_o have_v call_v the_o star_n i_o conceive_v to_o be_v dissolve_v equal_o on_o all_o side_n and_o the_o part_n which_o be_v dissolve_v or_o separate_v from_o it_o i_o conceive_v to_o fly_v every_o way_n from_o the_o centre_n of_o it_o with_o pretty_a near_o equal_a celerity_n or_o power_n like_v so_o many_o blaze_a granade_n or_o fire-ball_n these_o continue_v their_o motion_n so_o far_o towards_o the_o way_n they_o be_v shoot_v till_o the_o levitation_n from_o the_o body_n of_o the_o sun_n deflect_v they_o upward_o or_o in_o opposition_n to_o the_o sun_n into_o a_o parabolic_a curve_v in_o which_o parabolic_v curve_v every_o single_a particle_n continue_v its_o motion_n till_o it_o be_v whole_o burn_v out_o or_o dissolve_v into_o the_o aether_n these_o be_v continual_o succeed_v by_o new_a separation_n from_o the_o aforesaid_a body_n in_o the_o same_o manner_n as_o it_o be_v observable_a in_o a_o burn_a steam_a or_o smoke_a body_n in_o our_o air_n or_o a_o dissolve_v body_n encompass_v with_o its_o proper_a menstruum_fw-la as_o i_o before_o mention_v and_o will_v so_o continue_v until_o the_o whole_a be_v at_o length_n dissolve_v into_o the_o aether_n through_o which_o it_o pass_v it_o have_v be_v demonstrate_v by_o torricellius_n of_o bullet_n or_o other_o body_n cast_v or_o shoot_v upward_o that_o the_o same_o or_o equal_a bullet_n discharge_v or_o shoot_v out_o from_o the_o same_o point_n with_o the_o same_o degree_n of_o strength_n but_o with_o differ_v degree_n of_o inclination_n to_o the_o horizon_n each_o of_o they_o shall_v be_v move_v in_o a_o parabolical_a line_n and_o every_o one_o of_o those_o parabolical_a line_n shall_v touch_v a_o parabolical_a line_n who_o axis_fw-la be_v the_o perpendicular_a and_o who_o apex_n be_v distant_a from_o the_o say_a point_n the_o full_a altitude_n of_o the_o perpendicular_a shot_n so_o that_o suppose_v in_o the_o twenty_o second_o figure_n a_o to_o be_v the_o point_n from_o whence_o all_o the_o shot_n be_v make_v with_o equal_a velocity_n ac_fw-la the_o great_a height_n of_o the_o perpendicular_a shot_n and_o ad_fw-la the_o great_a horizontal_n random_n at_o 45_o degree_n of_o inclination_n and_o suppose_v edcde_v a_o parabola_fw-la pass_v through_o those_o point_n dcd_v all_o the_o shot_n make_v with_o equal_a bullet_n with_o equal_a velocity_n from_o a_o but_o with_o all_o variety_n of_o inclination_n between_o the_o perpendicular_a upward_o and_o the_o perpendicular_a downward_o that_o touch_v the_o say_v parabolical_a line_n and_o consequent_o if_o there_o be_v a_o indefinite_a number_n of_o such_o ball_n continual_o flow_v out_o of_o the_o point_n a_o with_o equal_a degree_n of_o celerity_n every_o way_n disperse_v themselves_o equal_o in_o orbem_fw-la the_o whole_a aggregate_v of_o such_o a_o emanation_n will_v make_v a_o solid_a parabolical_a conoeid_v edcde_v now_o about_o the_o point_n a_o if_o we_o suppose_v a_o sphere_n as_o bbbb_v and_o from_o this_o sphere_n a_o indefinite_a number_n of_o such_o equal_a ball_n be_v throw_v off_o perpendicular_o to_o the_o superficies_n of_o it_o from_o every_o point_n thereof_o with_o equal_a celerity_n at_o their_o leave_v it_o those_o emanation_n will_v form_v also_o a_o conoeid_v which_o will_v be_v very_o near_o the_o same_o with_o the_o former_a and_o if_o this_o ball_n in_o the_o middle_n be_v suppose_v a_o burn_a and_o shine_a body_n and_o that_o all_o these_o emanation_n have_v every_o one_o of_o they_o equal_a light_n in_o proportion_n to_o the_o globe_n bbbba_n the_o effect_n produce_v hereby_o will_v perfect_o resemble_v the_o appearance_n and_o figure_n of_o comet_n if_o at_o least_o the_o parabolical_a conoeid_v be_v invert_v which_o will_v somewhat_o explain_v the_o manner_n how_o i_o conceive_v the_o figure_n of_o the_o cometical_a body_n be_v natural_o and_o most_o proportionable_o form_v for_o if_o the_o effect_n of_o such_o a_o emanation_n of_o shine_a body_n be_v examine_v it_o will_v very_o plain_o exhibit_v the_o exact_a and_o true_a apparent_a figure_n of_o comet_n as_o they_o may_v be_v see_v through_o a_o good_a telescope_n which_o be_v to_o i_o a_o very_a great_a argument_n that_o it_o be_v the_o genuine_a cause_n of_o its_o shape_n and_o figure_n now_o though_o the_o comet_n appearance_n be_v this_o way_n cause_v and_o so_o a_o man_n may_v conceive_v the_o globous_a body_n will_v in_o a_o little_a time_n by_o so_o copious_a a_o emanation_n be_v consume_v yet_o i_o do_v not_o believe_v that_o it_o do_v in_o a_o short_a time_n waste_v and_o disperse_v the_o whole_a ball_n nor_o can_v i_o conceive_v that_o the_o disappear_v of_o those_o blaze_a body_n towards_o the_o latter_a end_n do_v depend_v upon_o their_o dissolution_n though_o possible_o that_o may_v somewhat_o diminish_v they_o but_o that_o rather_o be_v to_o be_v ascribe_v to_o their_o distance_n and_o position_n in_o respect_n of_o we_o though_o this_o i_o remember_v i_o observe_v very_o manifest_o in_o that_o of_o 1664._o that_o the_o body_n towards_o the_o latter_a end_n of_o its_o appear_v be_v very_o much_o less_o in_o proportion_n to_o the_o radiation_n about_o it_o than_o it_o seem_v to_o be_v at_o the_o beginning_n but_o whether_o that_o may_v not_o be_v partly_o ascribe_v to_o the_o great_a distance_n it_o then_o be_v from_o we_o and_o the_o turn_n of_o the_o head_n pretty_a near_o towards_o we_o and_o thence_o the_o spread_a of_o the_o tail_n appear_v beyond_o it_o may_v add_v to_o the_o breadth_n of_o the_o radiation_n about_o the_o nucleus_n i_o will_v not_o positive_o determine_v now_o though_o for_o explication_n sake_n i_o have_v compare_v the_o part_n separate_v from_o the_o body_n of_o the_o comet_n to_o blaze_a granade_n or_o fire-ball_n yet_o i_o will_v not_o be_v understand_v to_o suppose_v these_o part_n so_o separate_v to_o be_v of_o any_o very_a large_a bulk_n for_o i_o see_v no_o necessity_n to_o suppose_v they_o big_a than_o the_o atom_n of_o smoke_n or_o the_o particle_n of_o any_o other_o steam_a body_n or_o than_o the_o part_n of_o the_o air_n which_o make_v the_o body_n of_o it_o appear_v thick_a and_o hazy_a nor_o do_v i_o believe_v that_o all_o the_o light_n of_o the_o star_n head_n and_o blaze_n do_v depend_v only_o upon_o the_o shine_a of_o the_o dissolve_v body_n and_o particle_n thereof_o but_o i_o do_v suppose_v that_o it_o do_v proceed_v both_o from_o the_o reflection_n of_o the_o sunbeam_n from_o those_o part_n and_o also_o from_o a_o innate_a and_o momentaneous_a light_n produce_v by_o the_o action_n of_o dissolution_n wrought_v on_o the_o part_n by_o the_o encompass_v aether_n it_o may_v possible_o seem_v very_o difficult_a to_o suppose_v that_o the_o dissolution_n of_o the_o part_n of_o the_o nucleus_n by_o the_o encompass_v aether_n shall_v cause_v or_o impress_v so_o violent_a a_o motion_n into_o the_o separate_a part_n as_o to_o make_v they_o depart_v from_o it_o to_o the_o space_n of_o four_o or_o five_o diameter_n before_o it_o be_v overpower_v by_o the_o power_n of_o levitation_n from_o the_o body_n of_o the_o sun_n and_o so_o deflect_v into_o a_o parabolical_a line_n upward_o it_o may_v likewise_o seem_v strange_a to_o suppose_v that_o the_o aether_n shall_v have_v such_o power_n in_o it_o as_o first_o to_o dissolve_v a_o body_n into_o itself_o and_o second_o to_o cause_v a_o shine_a and_o three_o to_o cause_v a_o levitation_n of_o the_o dissolve_a part_n upward_o whereas_o i_o suppose_v before_o and_o i_o think_v it_o be_v very_o manifest_a that_o they_o cause_v a_o gravitation_n downward_o towards_o the_o centre_n of_o the_o sun_n but_o to_o these_o for_o explication_n i_o answer_v that_o we_o need_v not_o go_v far_o for_o instance_n to_o make_v these_o thing_n probable_a the_o atmosphere_n about_o the_o earth_n as_o i_o have_v former_o mention_v in_o my_o micrographia_fw-la i_o take_v to_o be_v nothing_o else_o but_o the_o dissolution_n of_o the_o part_n of_o the_o earth_n into_o the_o encompass_v aether_n for_o the_o proof_n of_o which_o i_o can_v bring_v many_o argument_n be_v it_o here_o a_o proper_a place_n by_o which_o i_o can_v most_o evident_o demonstrate_v the_o thing_n to_o be_v as_o i_o have_v assert_v it_o be_v here_o evident_a that_o this_o aether_n do_v take_v up_o the_o particle_n of_o body_n to_o a_o very_a great_a distance_n from_o the_o surface_n from_o which_o they_o be_v separate_v and_o it_o do_v not_o only_o raise_v they_o but_o sustein_v they_o at_o those_o height_n nor_o be_v this_o peculiar_a only_o to_o the_o aether_n when_o a_o menstruum_fw-la but_o to_o all_o dissolve_v menstruum_n in_o general_n as_o to_o give_v one_o instance_n in_o stead_n of_o many_o we_o find_v that_o gold_n the_o heavy_a of_o all_o terrestrial_a body_n we_o yet_o know_v be_v dissolve_v by_o aqua_fw-la regis_fw-la
may_v clear_o see_v such_o a_o fabric_n as_o be_v true_o very_o admirable_a and_o such_o as_o none_o hitherto_o have_v discover_v that_o ever_o i_o can_v meet_v with_o of_o which_o more_o hereafter_o when_o i_o show_v the_o true_a mechanical_a fabric_n thereof_o and_o what_o cause_v its_o motion_n thus_o if_o you_o view_v a_o thread_n of_o a_o ligament_n you_o shall_v plain_o see_v it_o to_o be_v make_v up_o of_o a_o infinite_a company_n of_o exceed_v small_a thread_n smooth_a and_o round_a lie_v close_o together_o each_o of_o which_o thread_n be_v not_o above_o a_o four_o hundred_o part_n of_o the_o bigness_n of_o a_o hair_n for_o compare_v those_o of_o beef_n with_o a_o hair_n of_o my_o head_n which_o be_v very_o fine_a and_o small_a viz._n about_o a_o 640._o part_n of_o a_o inch_n i_o find_v the_o diameter_n thereof_o to_o be_v more_o than_o twenty_o time_n the_o diameter_n of_o these_o thread_n so_o that_o no_o less_o than_o 163_o million_o beside_o 840_o thousand_o of_o these_o must_v be_v in_o a_o ligament_n one_o inch_n square_a i_o shall_v not_o here_o enlarge_v upon_o the_o admirable_a contrivance_n of_o nature_n in_o this_o particular_a nor_o say_v any_o thing_n far_o of_o the_o reason_n of_o the_o great_a strength_n of_o the_o same_o substance_n draw_v into_o small_a than_o into_o great_a thread_n but_o only_o this_o in_o general_a that_o the_o mechanical_a operation_n of_o these_o minute_n body_n be_v quite_o differ_v from_o those_o of_o body_n of_o great_a bulk_n and_o the_o want_n of_o consider_v this_o one_o thing_n have_v be_v the_o cause_n of_o very_o great_a absurdity_n in_o the_o hypothesis_n of_o some_o of_o our_o more_o eminent_a modern_a philosopher_n for_o he_o that_o imagine_v the_o action_n of_o these_o lesser_a body_n the_o same_o with_o those_o of_o the_o large_a and_o tractable_a body_n will_v indeed_o make_v but_o aristotle_n wooden_a hand_n at_o best_a this_o put_v i_o in_o mind_n likewise_o of_o advertise_v the_o experimenter_n that_o he_o provide_v himself_o with_o instrument_n by_o which_o to_o stretch_v and_o pull_v in_o piece_n any_o substance_n whilst_o the_o same_o be_v yet_o in_o view_n of_o the_o microscope_n of_o which_o there_o may_v be_v many_o which_o any_o one_o will_v easy_o contrive_v when_o he_o have_v this_o hint_n give_v he_o of_o the_o usefulness_n thereof_o in_o the_o examination_n of_o the_o texture_n of_o several_a substance_n as_o of_o tendon_n nerve_n muscle_n etc._n etc._n those_o i_o have_v make_v use_n of_o be_v make_v to_o open_v like_o a_o pair_n of_o tobacco_n tongue_n by_o two_o angular_a plate_n of_o thin_a brass_n rivet_v together_o which_o by_o pinch_v the_o opposite_a end_n will_v either_o open_a or_o shut_v at_o the_o other_o as_o i_o have_v occasion_n these_o have_v a_o part_n extend_v between_o the_o two_o top_n be_v fix_v at_o a_o due_a distance_n from_o the_o object-glass_n that_o the_o body_n extend_v between_o they_o may_v be_v distinct_o see_v then_o with_o my_o finger_n squeeze_v together_o the_o opposite_a end_n the_o other_o end_v open_v by_o which_o mean_n how_o the_o part_n stretch_v and_o shrink_v may_v be_v plain_o discover_v now_o as_o this_o be_v of_o use_n for_o some_o kind_n of_o substance_n so_o the_o two_o glass_n plate_n be_v for_o other_o and_o particular_o for_o squeeze_v of_o several_a substance_n between_o they_o so_o as_o to_o break_v they_o in_o piece_n as_o those_o little_a creature_n in_o pepper-water_n or_o the_o globule_n in_o blood_n milk_n phlegm_n etc._n etc._n whereby_o the_o part_n within_o they_o may_v yet_o far_o be_v inquire_v into_o as_o mr._n leeuwenhoeck_n i_o find_v have_v do_v by_o his_o late_a observation_n whether_o he_o make_v use_v of_o this_o way_n or_o some_o other_o i_o know_v not_o have_v thus_o give_v a_o description_n of_o the_o appurtenance_n it_o remain_v that_o i_o come_v to_o the_o description_n of_o the_o microscope_n itself_o which_o be_v the_o principal_a instrument_n and_o without_o which_o all_o the_o rest_n be_v insignificant_a the_o microscope_n than_o i_o design_v here_o to_o describe_v be_v only_o of_o two_o kind_n either_o single_a or_o double_a the_o single_a microscope_n i_o call_v that_o which_o consist_v only_o of_o one_o glass_n though_o it_o have_v a_o double_a refract_a superficies_n and_o the_o double_a one_o i_o call_v that_o which_o be_v compound_v of_o two_o glass_n though_o it_o have_v for_o the_o most_o part_n a_o quadruple_a refraction_n of_o the_o ray_n the_o single_a microscope_n than_o consist_v of_o one_o small_a lens_n so_o fasten_v into_o a_o cell_n that_o the_o eye_n may_v come_v convenient_o to_o look_v through_o the_o middle_a part_n or_o axis_n of_o it_o of_o these_o there_o be_v various_a sort_n as_o double_a convex_n or_o plain_a convex_n or_o perfect_o spherical_a i_o shall_v not_o need_v to_o describe_v the_o common_a lense_v which_o be_v every_o where_o make_v use_v of_o for_o this_o purpose_n be_v plano-convexes_a of_o sphere_n about_o half_a a_o inch_n diameter_n save_v only_o this_o that_o it_o be_v best_a to_o turn_v the_o plain_a side_n towards_o the_o object_n and_o the_o convex_a to_o the_o eye_n nor_o shall_v i_o say_v much_o concern_v those_o double_a convex_a glass_n there_o be_v no_o great_a difficulty_n in_o the_o make_n or_o use_v of_o they_o but_o that_o the_o small_a the_o sphere_n be_v in_o which_o they_o be_v make_v the_o near_a do_v they_o bring_v the_o object_n to_o the_o eye_n and_o consequent_o the_o more_o be_v the_o object_n magnify_v and_o the_o better_a and_o true_a they_o be_v polish_a in_o the_o tool_n the_o more_o clear_a and_o distinct_a do_v the_o object_n appear_v but_o to_o make_v any_o of_o a_o sphere_n less_o than_o 1_o 10_o of_o a_o inch_n in_o diameter_n be_v exceed_o difficult_a by_o reason_n that_o the_o glass_n become_v too_o small_a to_o be_v tractable_a and_o it_o be_v very_o difficult_a to_o find_v a_o cement_n that_o will_v hold_v it_o fast_o whilst_o it_o be_v complete_v and_o when_o it_o be_v polish_a it_o be_v exceed_o difficult_a to_o handle_v and_o put_v into_o its_o cell_n beside_o i_o have_v find_v the_o use_n of_o they_o offensive_a to_o my_o eye_n and_o to_o have_v much_o strain_v and_o weaken_v the_o sight_n which_o be_v the_o reason_n why_o i_o omit_v to_o make_v use_n of_o they_o though_o in_o truth_n they_o do_v make_v the_o object_n appear_v much_o more_o clear_a and_o distinct_a and_o magnify_v as_o much_o as_o the_o double_a microscope_n nay_o to_o those_o who_o eye_n can_v well_o endure_v it_o it_o be_v possible_a with_o a_o single_a microscope_n to_o make_v discovery_n much_o better_o than_o with_o a_o double_a one_o because_o the_o colour_n which_o do_v much_o disturb_v the_o clear_a vision_n in_o double_a microscope_n be_v clear_o avoid_v and_o prevent_v in_o the_o single_a the_o single_a microscope_n therefore_o which_o i_o shall_v here_o describe_v as_o it_o be_v exceed_o easy_a to_o make_v so_o be_v it_o much_o more_o tractable_a than_o the_o double_a convex_a glass_n make_v the_o common_a way_n by_o work_v they_o in_o a_o hollow_a hemisphere_n with_o water_n and_o sand_n for_o those_o suppose_v they_o make_v with_o all_o the_o accurateness_n imaginable_a will_v be_v far_o short_a from_o be_v so_o well_o polish_a as_o these_o and_o want_v the_o stem_n or_o handle_v which_o these_o have_v they_o be_v infinite_o troublesome_a to_o remove_v or_o place_n or_o to_o cleanse_v when_o there_o shall_v be_v occasion_n take_v then_o a_o small_a rod_n of_o the_o clear_a and_o clean_a glass_n you_o can_v procure_v free_a if_o possible_a from_o blebb_n sand_n or_o vein_n then_o by_o melt_v it_o in_o the_o flame_n of_o a_o lamp_n make_v with_o spirit_n of_o wine_n or_o the_o clean_a and_o pure_a salad_n oil_n draw_v it_o out_o into_o exceed_v fine_a and_o small_a thread_n then_o take_v a_o small_a piece_n of_o these_o thread_n and_o in_o the_o same_o flame_n of_o the_o aforesaid_a lamp_n melt_v the_o end_n of_o it_o till_o you_o perceive_v it_o to_o run_v into_o a_o little_a ball_n or_o globule_n of_o the_o bigness_n desire_v then_o suffer_v it_o to_o cool_v and_o handle_v it_o by_o the_o aforesaid_a thread_n of_o glass_n which_o be_v as_o it_o be_v a_o handle_n to_o it_o fix_v it_o with_o a_o little_a wax_n upon_o the_o side_n of_o a_o thin_a plate_n of_o brass_n silver_n or_o the_o like_a that_o the_o middle_n of_o it_o may_v lie_v direct_o over_o the_o middle_n of_o a_o small_a hole_n prick_v through_o the_o say_v thin_a plate_n with_o a_o needle_n then_o hold_v this_o plate_n close_o to_o the_o eye_n look_v through_o the_o say_v little_a hole_n and_o thereby_o you_o may_v also_o see_v very_o clear_o through_o the_o aforesaid_a globule_n fix_v with_o wax_n on_o the_o side_n that_o be_v