The Contents.
A way of Preserving Birds taken out of the Egge, and other small Fetus's; communicated by Mr. Boyle. An Extract of a Letter, lately sent to Sr. Robert Moray out of Virginia, concerning an unusuall way of Propagating Mulberry-trees there, for the better improvement of the Silk-Work; together with some other particulars, tending to the good of that Royall Plantation. A Method, by which a Glass of a small Plano-Convex Sphere may be made to refract the Rayes of Light to a Focus of a far greater distance, than is usuall. Observations about Shining Worms in Oysters. Observations of the Effects of Touch and Friction. Some particulars, communicated from forrain Parts, concerning the Permanent Spott in Jupiter; and a contest between two Artists about Optick-Glasses, &c. An Account of a Book written by Dr. Thomas Sydenham, entituled, Methodus Curandi Febres, propriis Observationibus superstructa.
A way of preserving Birds taken out of the Egge, and other small Fætus's; communicated by Mr. Boyle.
This was imparted in a Letter, as follows;
The time of the year invites me to intimate to you, that among the other Uses of the Experiment, I long since presented the Society, of preserving Whelps taken out of the Dams womb, and other Fætus's, or parts of them, in Spirit of Wine; I
remember, I did, when I was sollicitous to observe the Processe of Nature in the Formation of a Chick, open Hens Eggs, some at such a day, and some at other daies after the beginning of the Incubation, and carefully taking out the Embryo's, embalmed each of them in a distinct Glass (which is to be carefully stopt) in Spirit of Wine: Which I did, that so I might have them in readinesse, to make on them, at any time, the Observations, I thought them capable of affording; and to let my Friends at other seasons of the year, see, both the differing appearances of the Chick at the third, fourth, seventh, fourteenth, or other daies, after the Eggs had been sate on, and (especially) some particulars not obvious in Chickens, that go about; as the hanging of the Gutts out of the Abdomen, &c. How long the tender Embryo of the Chick soon after the Punctum saliens is discoverable, and whilst the Body seems but a little Organized Gelly, and some while after That, will be this way preserv'd, without being too much shrivel'd up, I was hindred by some mischances to satisfie my self: but when the Fætus's, I took out, were so perfectly formed as they were wont to be about the seventh day, and after, they so well retain'd their shape and bulk, as to make me not repent of my curiosity: And some of those, which I did very early this Spring, I can yet shew you. I know I have mention'd to you an easie application of what I, some year since, made publick enough; but not finding it to have been yet made by any other, and being perswaded by Experience, that it may be extended to other Fætus's, which this season (the Spring) is time to make provision off, I think the Advertisement will not seem unseasonable to some of our Friends; though being now in haste, and having in my thoughts divers particulars, relating to this way of Preserving Birds taken out of the Egge, and other small Fætus's, I must content my self to have mention'd that, which is Essential, leaving divers other things, which a little practise may teach the Curious, unmention'd. Notwithstanding which, I must not omit these two Circumstances; the one, that when the Chick was grown big, before I took it out of the Egge, I have (but not constantly)
* In the Usefulness of Experimental Philosophy. mingled with the Spirit of Wine, a little Spirit of Sal Armoniack, made (as I have elsewhere delivered) * by the help of Quick-lime: which Spirit I choose, because, though it abounds in a Salt not Sowre, but Urinous, yet I never observed it (how strong soever I made it) to coagulate Spirit of Wine. The other circumstance is, that I usually found it convenient, to let the little Animals, I meant to imbalme, lie for a little while in ordinary Spirit of Wine, to wash off the looser filth, that is wont to adhere to the Chick, when taken out of the Egge; and then, having put either the same kind of Spirit, or better upon the same Bird, I suffer'd it to soak some hours (perhaps some daies, pro re nata) therein, that the Liquor, having drawn as it were what Tincture it could, the Fætus being remov'd into more pure and well dephlegm'd Spirit of Wine, might not discolour it, but leave it almost as limpid, as before it was put in.