_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 _Faetus's_; communicated by _Mr. Boyle_._ This was imparted in a Letter, as follows; [Sidenote: * _In the Usefulness of Experimental Philosophy._] 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 _Faetus's_, or parts of them, in _Spirit of Wine_; I {200} 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 _Faetus'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