§ 21. Therefore he first Attacks the Pericardium, which, after a long tryal and a great deal of pains, he made shift to tear; and when he had laid the Heart bare, and perceiv'd that it was solid on every side, he began to examin it, to see if he could find any hurt in it; but finding none, he squeez'd it with his Hands, and perceiv'd that it was hollow. He began than to think that what he look'd for, might possibly be contain'd in that Cavity. When he came to open it, he found in it two Cavities, one on the right side, the other on the left. That on the right side was full of clotted Blood, that on the left quite empty. "Then (says he,) without all doubt, one of those two Cavites must needs be the Receptacle of what I I look for; as for that on this side there's nothing in it but congealed Blood, which was not so, be sure, till the whole Body was in that condition in. which it now is" (for he had observ'd that all Blood congeals when it flows from the Body, and that this Blood did not differ in the least from any other,) "and therefore what I look for, cannot by any means, be such a matter as this; for that which I mean, is something which is peculiar to this place, which I find I could not subsist without, so much as the Twinkling of an Eye. And this is that which I look'd for at first. For as for this Blood, how often have I lost a great deal of it in my Skirmishes with the Wild Beasts, and yet it never did me any considerable harm, nor rendred me incapable of performing any Action of Life, and therefore what I look for is not in this Cavity. Now as for the Cavity on the left side, I find 'tis altogether empty, and I have no reason in the World to think that it was made in vain, because I find every part appointed for such and such particular Functions. How then can this Ventricle of the Heart, which I see is of so excellent a Frame, serve for no use at all? I cannot think but that the same thing which I am in search of, once dwelt here, but has now deserted his Habitation and left it empty, and that the Absence of that thing, has occasion'd this Privation of Sense and Cessation of Motion, which happen'd to the Body." Now when he perceiv'd that the Being which had inhabited there before, had left its House before it fell to Ruine, and forsaken it when as yet it continu'd whole and entire, he concluded that it was highly probable that it would never return to it any more, after its being so cut and mangled.
§ 22. Upon this the whole Body seem'd to him a very inconsiderable thing, and worth nothing in respect of that Being, he believed once inhabited, and now had left it. Therefore he applied himself wholly to the consideration of that Being. What it was? and how it subsisted? what joyn'd it to the Body? Whether it went, and by what passage, when it left the Body? What was the Cause of its Departure, whether it were forc'd to leave its Mansion, or left the Body of its own accord? and in case it went away Voluntarily, what it was that rendred the Body so disagreeable to it, as to make it forsake it? And whilst his Mind was perplext with such variety of Thoughts, he laid aside all concern for the Carcass, and threw it away; for now he perceiv'd that his Mother, which had Nurs'd him so Tenderly and had Suckled him, was that something which was departed: and from it proceeded all those Actions by which she shew'd her Care of him, and Affection, to him, and not from this unactive Body; but that the Body was to it only as an Instrument or Tool, like his Cudgel which he had made for himself, with which he used to Fight with the Wild Beasts. So that now, all his regard to the Body was remov'd, and transferr'd to that by which the Body is governed, and by whose Power it moves. Nor had he any other desire but to make enquiry after that.
§ 23. In the mean, time the Carcass of the Roe began to putrifie, and emit Noisome Vapours, which still increas'd his aversion to it, so that he did not care to see it. 'Twas not long after that he chanc'd to see two Ravens engag'd so furiously; that one of them struck down the other Stark Dead; and when he had done, he began to scrape with his Claws till he had digg'd a Pit, in which he Buried the Carcass of his Adversary. Our Philosopher observing this, said to himself, How well has this Raven done in Burying the Body of his Companion, tho' he did ill in Killing him? How much greater reason was there for me to have been forward in performing this Office to my Mother? Upon this he makes a Grave, and lays his Mother into it, and Buries her. He proceeded in his Enquiry concerning what that should be by which the Body was govern'd, but could not Apprehend what it was; when he look'd upon the rest of the Roes, and perceiv'd that they were of the same form and figure with his Mother, he believ'd that there was in every one of them something which govern'd and actuated them, like that which had actuated and govern'd his Mother: formerly: and for the sake of that likeness he us'd to keep in their Company, and shew affection towards them. He continued a while in this condition, Contemplating the various kinds of Animals and Plants, and walking about the Coast of his Island, to see if he could find any thing like himself; (as he observ'd that every Individual Animal, and Plant, had a great many more like it.) But all his search was in vain. And when he perceiv'd that his Island was encompass'd by the Sea, he thought that there was no other Land in the World but only that Island.
§ 24. It happen'd that by Collision a Fire was kindled among a parcel of Reeds or Canes; which fear'd him at first, as being a Sight which he was altogether a Stranger to; so that he stood at a distance a good while, strangely surpriz'd, at last he came nearer and nearer by degrees, still observing the Brightness of its Light and marvellous Efficacy in consuming every thing it touch'd, and changing it into its own Nature; till at last, his Admiration of it, and that innate Boldness and Fortitude, which God had implanted in his Nature prompted him on, that he ventur'd to come near it, and stretch'd out his Hand to take some of it. But when it burnt his Fingers and he found there was no dealing with it that way, he endeavour'd to take a stick, which the Fire had not as yet wholly seiz'd upon; so taking hold on that part which was untouch'd he easily gain'd his purpose, and carried it Home to his Lodging (for he had contriv'd for himself a convenient place) there he kept this Fire and added Fuel to it, admir'd it wonderfully, and tended it night and day; at night especially, because its Light and Heat supply'd the absence of the Sun; so that he was extreamly delighted with it, and reckon'd it the most excellent of all those things which he had about him. And when he observ'd that it always mov'd upwards, he perswaded himself that, it was one of those Celestial Substances which he saw shining in the Firmament, and he was continually trying of its power, by throwing things into it, which he perceiv'd it operated upon and consum'd, sometimes sooner, sometimes slower, according as the Bodies which he put into it were more or less combustible.
§ 25. Amongst other things which he put in to try its strength, he once flung in some Fish which had been thrown a-shore by the Water, and as soon as e're he smelt the Steam, it rais'd his Appetite, so that he had a Mind to Taste of them; which he did, and found 'em very agreeable and from that time he began to use himself to the Eating of Flesh, and applied himself to Fishing and Hunting till he understood those sports very well: upon this account he admir'd his Fire more and more, because it help'd him to several sorts of Provision which he was altogether unacquainted with before.
§ 26. And now when his Affection towards it was increas'd to the highest degree, both upon the account of its Beneficial Effects, and its Extraordinary Power; he began to think that the Substance which was departed from the Heart of his Mother the Roe, was, if not the very same with it, yet at least of a Nature very much like it. He was confirm'd in his Opinion, because he had observ'd in all Animals, that as long as they liv'd, they were constantly warm without any Intermission, and as constantly Cold after Death, Besides he found in himself, that there was a greater degree of Heat by much in his Breast, near that place where he had made the Incision in the Roe. This made him think that if he could dissect any Animal alive, and look into that Ventricle which he had found empty when he dissected his Dam the Roe, he might possibly find it full of that Substance which inhabited it, and so inform himself whether it were of the Substance with the Fire, and whether it had any Light or Heat in it or not. In order to this he took a Wild Beast and ty'd him down, so that he could not stir, and dissected him after the same manner he had dissected the Roe, till he came to the Heart; and Essaying the left Ventricle first, and opening it, he perceiv'd it was full of an Airy Vapour, which look'd like a little Mist or white Cloud, and putting in his Finger, he found it hotter than he could well endure it, and immediately the Creature Dyed. From whence he assuredly concluded, that it was that Moist Vapour which communicated Motion to that Animal, and that there was accordingly in every Animal of what kind soever, something like it upon the departure of which Death follow'd.
§ 27. He had then a great desire to enquire into the other parts of Animals, to find out their Order and Situation, their Quantity and the manner of there Connexion one with another, and by what means of Communication they enjoy the Benefit of that Moist Vapour, so as to live by it. How that Vapour is continu'd the time it remains, from whence it has its Supplies, and by what Means its Heat is preserv'd. The way which he us'd in this Enquiry was the Dissection of all sorts of Animals, as well Living as Dead, neither did he leave off to make an accurate Enquiry into them, till at length he arrived to the highest degree of Knowledge in this kind which the most Learned Naturalists ever attain'd to.