like its Serum but of both a very small quantity I search'd the Ductus Salivares and their Glandulae for this Water all which appearing very white and nothing yellowish at all in them their whiteness I suppose they received from the pure whiteness of the Saliva contained in them And thus I was as I thought frustrate of finding the clear Liquor before-mentioned for from the Nerves or Lymphatick Vessels although they were visible enough yet for many reasons I thought it most improbable for any of them to carry such a Liquor forth unto the Teeth In the next biting of an Adder I observed two things First That she held her Chaps in the very instant of biting to the place she bit upon so exactly close that nothing either of Breath or Water could pass out that way her Mouth and Lips seeming naturally fitted for that purpose Secondly I discerned an apparent Motion of Expiration at the very instant of biting which being upon the Throat of a strong Dog of a thick Skin I suppose the Teeth entred only the two Skins and yet a Tumor presently arose to the bigness of a large Bladder whereupon I caused that Adder and another to bite the same Dog in another place always taking care at the time of biting to hinder expiration some way or other as well as I could and I always found that either the biting had no Effect or else the Adder had no mind to bite though never so much inraged before nay though with great force I squeezed the Teeth into the place they were fastned unto that they might enter very deep holding his Chaps very hard together between my Finger and Thumb and pressing both the over and lower Jaw together yet no considerable Effect would follow except the Adder had the liberty of his own way of biting and close shutting of his Lips to the bitten place Whereupon I began for to suspect that the very dangerous biting of our Adder was truly caused from her Breath and the close shutting of her Mouth and forcing either depraved Breath or the steams of such Breath into the Body by those little Orifices which the very action of biting seemed more fully to declare In which Opinion I was the more confirmed when inspecting the Wind-pipe I found two great Recipients for Air but the Lungs so conveniently situate in this Animal as it were to deprive the descending Air of the greatest part of this Aereal Salt which they naturally will do beyond any thing that Art can perform And therefore saith a learned Author Aer è pulmonibus egestus respirationi vitaeque sustentandae nequaquam idoneus est Circa respirationis ergo usum affirmare fas sit nonnihil quicquid sit Aereum ad vitam sustinendam necessarium in sanguinis massam transire Hinc Aer è pulmonibus egestus è quo particulae istae Vitales exhauriuntur non amplius ad respirationem idoneus est And the Air being thus deprived we may from what I have said conclude that it will naturally deprave for as the Air in Mines deprived of this Nitrous Salt and pent close up is the true Damp so this Air in our Adder deprived by the Lungs of its wholesome parts is the true Venom or Verulency as some phrase it For By the contraction of this long Bladder and of their neat Anulares together with the extraordinary length of their Wind-pipe and the close shutting of their Mouths to the place bitten the deprived Air is forc'd with their Teeth into the wounded or bitten place and by this Motion through the Wind-pipe either from the Sides or Glandulae bring that clear Lympha along with it And thus having given a considerable instance to shew the true Nature of a Pestilential Constitution to consist in an Aereal Deprivation arising from a Defect of this Salt 't is as easie to conceive as in the Adder how the same Deficiency is made in the Air we breath in and what Effect that Deficiency will have upon the Humors of our Body I do not by all this deny the Existence of several Subterraneous Steams or Exhalations no question but that they are ready to croud in upon the least defect of this Aereal Salt and to render the Air more or less depraved either as the Air is more or less defective to make room for them or they in their own Nature are more or less pernicious For as in Subterraneous Damps according to the different Nature or Quality of the Mines so on the Surface of the Earth according to the variety of the Soils on the defect of these Nitro-Aereal Particles several Heterogeneous Steams do get into their places and very ill supply the defect of this most useful Salt CHAP. VI. BUt some may enquire perhaps from whence all this Nitro-Aereal Salt should come with which it is very manifest the Air we breath does so plentifully abound In answer to which Enquiry I do confeses I am inclined to believe that this Nitro-Aereal Salt which does so evidently abound in wholsom Air is Chymically raised and sublimed from the Sea by the Sun's Heat the more Volatile part carrying with it the grosser part before-mentioned And this I am still more inclined to believe when I consider Salt-Petre it self is only Sal Gemma or Sea Salt more abounding with Volatile Aereal Spirits as indeed there is great reason for it why it should Others may enquire what it is that does most cause a Defect and consequently an ill and a depraved Air To which I answer Not all those Mutations of the Air observed by Hippocrates and his followers nor all those notable Alterations of the Air mentioned more particularly by Silvius de le Boe and his Scholars have this Operation or Effect upon the Air as by diligent Observation I can yet find but only some of them have especially an extreme great long or lasting cold Frost An extreme great long and lasting Heat Driness or Moisture in the like manner any one of these accompanied with a long quietness or tranquility of the Air may first cause a Defect c. As for Example in the canicular Days when the over-violent Sun's heat hath too much rarified and sublimed this Salt that we can scarcely breath then Defects and Depravations Death and Ruine are very apt to follow one another which have much sooner an Effect on some Constitutions than others according to the various Consistency or Dislocation Combination or Relaxation Firmness or Weakness of the Particles of the Blood or Humors And this I take to be the true reason of our so frequent Autumnal Epidemick Fevers although they are perhaps not suddenly felt at that time in the Canicular Days but stay longer before they appear they are so much the worse for it and argue that the former Deprivation has had a longer time to deprave according as it falls out sometimes to deprave both the Air and Humors of our Body and when the returning Cold and more plentiful Aereal
Attenuation and Dilution of the Chyle without any preternatural Commotion to disorder or disturb one another Nor does the Blood quarrel with the well prepared Chyle but amicably receives it from the Ductus Thoracicus into the Subclavian Vein and as amicably passes with it into the right Ventricle of the Heart where though in the Diastole they are more mixt together yet they stay not to make that bustle some have thought but by the Systole or Contraction of the Heart are soon driven out again the Chyle accompanying the Blood to the greatest amongst all the Viscera for Sanguification I mean the Lungs where they both receive a florid Red and by the admission of new Particles are more perfectly assimulated or united with each other So that even in Fevers which seem to give the greatest disturbance to the Humors of our Body the disturbance does not first arise from a quarrel raised amongst the Humors of our Body for as long as no strange ill Guest comes in to disturb them they all perform their natural offices in their wonted order but if they are hindred or disturbed in their Operations by an Enemy they then fall into tumult and disorder The Blood does not quarrel with its self nor one part of it with another for really there is no Fermentation truly and properly so called in it neither according to the supposed Fermentation does one part act upon or against another For I consider the Blood not as it is Chymically analyzed into their Principles but as it is a viscous Humor whose Particles are not fermented but combined together by an Aereal Salt receiving Heat from its own Motion and Circulation round the Body whose Recrements are separated from it by the various and admirable Contexture and Configuration of the Vessels through which they pass whilst the viscid Humor or thick part of the Blood keeps close and entire and by the Anastomases which I suppose whether visible or not of the Veins and Arteries is brought back to the Heart a languid Pulse being continued by the extremities of the Arteries to every Vessel which helps forward the Separation Secretion Percolation or which you shall please to call it of the thinner Humors I shall not stay here further to shew either the incapacity of the Blood or unfitness of the Vessels through which it passes nor the danger of such Heterogeneous fermenting Liquors especially near the extremity of such small fine and thin Vessels through which these Liquors of such different fermenting Particles must violently pass neither shall I shew how the Viper and several other Animals that sleep all Winter whose Blood is not denied to Circulate all that while neither void any Excrements all that while nor is their Bladder of Gall fuller when they first come forth in the Spring than when in Winter they first took their Beds to demonstrate that either the Blood does not always Ferment or that the Gall is not thrown off by such a Fermentation So that as I cannot believe Diseases with the Ancients so often to arise from the solid Parts nor the Blood to consist of their four Humors neither can I believe such a bustle kept in our Body as hath of late been talkt of I neither believe the solid Parts nor Humors of our Body to conspire our ruine CHAP. II. SO that whatever Commotion Fermentation Ebullition or Disturbance there is raised in the Blood or Humors must arise preternaturally and ab extra for else neither Blood nor Humors will of themselves raise such violent Commontions or Disturbance in Man's Body It is unquestionably true That the Air above all the other Non-naturals is the great Cause of our Epidemick Fevers the best way therefore to know the nature of such Fevers next to the knowledge of the Blood will be to consider the Nature of the Air we breath in I shall not enlarge here concerning the various Opinions of Philosophers concerning the Nature of Air neither shall I determine from whence it does arise or of what composed it being two larger discourse for my present purpose but I shall only suppose the Air to be a very thin and fluid Body combined most strictly with a Nitrous Salt and by the pressure of other Particles together with its own natural fineness and subtilty pervading every Patulous Pore in Earth and Water I say Patulous because I deny not nay I affirm there are many Pores especially in the Earth which the Aereal Particles are not fine enough to enter and indeed both Earth and Water do resist its penetration but not with equal force for the Air cannot enter very far into the more strictly united and combined Particles of Earth but the grosser parts of the Aereal Salt are necessitated to stick fast from whence with easie trouble we extract our common Niter Whereas the Particles of Water being more flexile and not so closely combined together recede and give way to its penetration So that this Aereal Salt enters to the bottom of the deepest Waters without which the very Eels though bedded in the Mud cannot live and Carps have been known to live by Air only two or three days out of Water both which Experiments are best manifest in extreme cold and frosty times when the Ice does prevent the ingress of Aereal Particles into the bottom of the Water and the Cold does condense them for the others preservation In great Frosts I have known in Ponds quite frozen over multitude of Fishes for want of Air sometimes as it were smothered sometimes sick and faintly swimming towards small vent-holes where Air was let in to them by breaking the Ice to keep them alive But to this I have heard some answer That they have never broke their Pools at all add yet their Fish have done well and it may be so sometimes for in a great Frost the Water is very apt to sink from the Ice and leave a hollow in the sides for the Air to enter and I have been certainly told of Eels that have crept out of the Deep and their warmer Mud-beds for want of Air and have lain dead at the sides in the extreme cold Winter Which had they been so much offended with cold as some have thought they are they might easily have kept their former stations and so have remained ab hac coeli inclementia tuti Or else perhaps such Pools had Quick-springs running into them unto the heads of which Springs the Eels will commonly swim up for Air when the body of the Pool is quite froze over Where by the bye let me also make this further Observation That the greater and more subtle Fish tho' they swim near the bottom yet they chuse to be directly under those holes by which it is apparent that these Aereal Particles are neither reflected nor refracted but by the interposition of another body which they cannot enter being otherwise press'd directly downward But to return CHAP. III. THe Air having this penetrating force upon Earth and Water
let us next enquire how it does enter human Bodies And there are four ways by which it is commonly believed the Air may enter them Either First By its Mixing its self with what we eat and so is carried to the Stomach Or Secondly It is received by Inspiration into the Lungs and so is carried to the Heart Or. Thirdly By the Pores of the Body and from thence to the Mass of Blood Or Lastly In Inspiration to the Ventricles of the Brain The two first of which I think are only true As to the First I think it is undoubtedly true That the Air does or Aereal Particles do mix themselves with what we eat for whatever we eat must have numerous Pores or else we could never chew it with out Teeth nor digest it in our Stomach or separate Chyle from it and I believe the Air may sometimes enter these Pores however it does enter the Mouth and is pressed down the Oesophagus either by the Aliment or force of the Aereal Atoms naturally descending downward Secondly It is apparent both by dissection and inflation of the Lungs that the Air does enter from the Larnix and Bronchia into the Vesiculary Cells and there whether by Adhesion of Dissolution does deposite at least some part of this Aereal Salt where meeting with the occurring Humors is directly carried to the Heart and by its pungent Particles molesting and irritating the streight and oblique Fibres of the Heart does stir them up into a Systole or Contraction and so by streightning its Ventricles to drive forth the Blood contained in them into the Arteries And this I take to be the true Original of all Pulsation and first Motion of the Heart and Circulation of the Blood throughout the Body For when I observe the Motion of the Hearts of several Creatures exempt from their Bodies and exposed to the open Air I can never believe either the Influx of Animal Spirits much less the Ebullition Accension or Dilatation of the Heart to be the Cause of its Motion but rather the Effect of these pungent Particles pricking upon the Fibrous Parenchyma of the Heart in their natural descending Motion As to the other two ways of receiving Air viz. by the Pores of the Body when I consider the Nature of these Atoms pressing directly downward when I consider the great Quantity of Effluvia that are continually transpired by the Cuticulary Pores when I consider the Nature of those Pores and their action to be continued suitable to the utmost extremity of the Arteries from whence they originally are derived I cannot see how the Air can enter without either penetratione Corporum or an inversion of Natures constant Course à centro ad circumferentiam Corporis The Arguments that are brought to prove the Porosity of Animals by the taking in of Effluvia from without by the application of Oils and Plasters if rightly considered make nothing to this purpose to prove the entrance of this Aereal Salt by the Cuticulary Pores for setting aside a particular enquiry into the Nature of those Plasters their subtile active igneous violent cooling drying irritating stupifying obstructing and preternaturally disposing Particles the Cuticulary Pores are not placed for the due reception of this Salt nor have the points of this Salt a force upon them since they naturally descend perpendicularly downward Neither when I observe the difference between the Florid Aereal Coloured Blood returning from the Lungs and the Atropurpureal Blood contained in the Veins can I believe this Aereal Salt does enter by the Pores or is mixt with the Venal Blood when I see the Venal Blood both changed in colour and consistence from what I either find in the Lungs or Arteries And as to the last of these ways when the Authors acquaint us how the Particles of Air are parted assunder in Inspiration part of them ascending by the Mammillary Processes ad cerebri Vasa Ventriculos and part descending to the Pulmonary Vessels when they can I say explicate with any great probability how this is done for what end or use the Air thus impregnated with this Salt should come thither it will deserve further Consideration For Although the Mammillary Processes may be affected by the Points of this Salt and according to the various and different Modification of them so various and different smells may be conveyed unto the Brain Nay although the Particles of this Salt are very different as to their shape and bigness size and figure yet do I not see how nor for what end or use by these nervous Processes they should ever be conveyed neither can I see how these Nerves or even the Brain it self should escape a strong Vellication by them which being communicated by the Nerves might cause a Convulsive Motion in every Member in the Body CHAP. IV. NOw as I have owned but only two ways by which this Aereal Salt can be received into human Bodies so do I very much question whether any thing else is left in a healthy Air to joyn either with Chyle or Blood but this Aereal modified Salt only which of its self is able to produce these great and following Effects First This Salt as it is variously mixt or modified by the Aliment we take into our Mouths so different Tastes appear unto us and either descending or prest down by other Particles causes that disturbing Vellication on the inner Membrane of the Nerves that seem as it were placed there on purpose to communicate that Vellication to the Brain do occasion that Desire in us which we call Hunger and from hence the taking the fresh Air does make us hungry because we then receive this Aereal Salt both into our Lungs and Stomach But 't is not the Fibres of the upper Orifice alone but descending to the bottom of the Stomach with the Aliment or what we eat it has the same Operation on the other Fibres and moves them to eject out at the Pylorus and irritating all along on the Fibres of the Intestines is a great cause of and a considerable advantage to their Peristaltick Motion But though this Salt is so highly useful to the Motion of the Stomach yet the Stomachical Operations are not performed by it alone for I have observed near the Rugae of great Animals certain Papillae and a constant Juyce lodged in them which I believed to be an acid Lympha brought thither by invisible Lymphatick Vessels which we have great reason to believe do moisten the Fibrous Tunicles of the Ventricles although they are not perceptible to our sight I know I might have traced the generation of Animals and have shewn not only how the prima stamina vitae the Motion of the punctum saliens nay even the birth it self is owing to this Salt As likewise I might shew the Effects of different occurring Salts that meet together in the Duodenum But designing brevity I must hasten next to shew what great Effects this Nitrous Salt doth commonly produce upon our