Page:Philosophical Transactions - Volume 004.djvu/259

 ther vertues by the several kinds of Barks &c? The Tan ne know, that the bark of some Trees hath much more Salt than the Timber: And generally where the Barks have the stronger or finer relish or Vertue, the Wood hath very little. The wood of the Cinamond-tree is Insipid; And the wood of Guaiacum hath not halfe that vertue which the Bark hath. But in these trials we should take heed of a danger from the compressed steams. And if we would use a deep and dry Well, for strong heate by Marcasires, or otherwise, we should remember Mr Boyle's proofs of the Incredible weight of the Air, and provide very strong Arches and thick Planks for the Coverture, before we adventure to stop in the Air, when it is highly rarifyed by such heates.

8. Bur than which chiefly encouraged me to give you these remarkes of the operations of Frosts and Cold, is this. It growes in fashion to make Conservatories for Snow and Ice; and Mr Boyle hath layd such deep Foundations to find out the Nature, propertyes, and effects of Cold and Frosts, that we may almost hope, that by this branch of Philosophy, when it shall be as carefully Cultivated, as Chymistry now is, we may perform as much, if not more and stranger things than are yet done by Fire. I do often ask Gardeners, and skilful Husbandmen, whether all forms of Land are more fertiliz'd, or more speedily, by the solar Influence in our Climate, or by Frosts. For these two are the two busy hands, which manure all kinds of Earth and Water into grateful pregnancy, as Virgil of Old,

And they generally affirm, that Frost and Snow make the quicker dispatch amongst us, and the more general and richer Fertility. And, that some Distillations may be made by Frosts, I have this proof: At my request you were pleass'd to get me a Thermometer of a very smal and slender Stem, especially the higher parts for 10 Inches near the head: All that see it, do wonder how such a slender Glass could be safely conveighed hither The Spirit of wine is very deeply tinged, which renders it in that smalness clearly visible: I exposed it out of Doors in the hardest Frosts of the extreame winter Anno 1665. when the