Page:History of the Royal Society.djvu/301

 in a Crucible, and burn off the volatile part with Powder of Coal, Brimstone, Antimony or Meal, there will remain a Salt, and yet so fixed (very unlike Common-Salt) that it will endure the force of almost the strongest Fire you can give it; which being dissolved into Water and Spirit of Nitre dropped into it, till it give over hissing (which is the same with the volatile Part that was separated from it in the fulmination) it will be again reduced to Chrystals of Peter as it was at first; which noble Experiment the World hath already been taught by an honourable Member of this Society; with a train of such important Observations, as never before were raised from one Experiment.

'That which I aim at then is, that if the Spirit of the volatile Salt of Soot, or of the Urine, Blood, Horns, Hoofs, Hair, Excrements, or indeed any part of Animals (for all abound with such a volatile Salt fixed, and Oyl as Peter doth) could by the same way, or any like it, be reduc'd to Peter or some Nitrous Salt not much differing from it: It would excellently make out a Theory that I am much delighted with, till I am convinced in it; which is, that the Salt which is found in Vegetables and Animals, is but the Nitre which is so universally diffused through all the Elements (and must therefore make a chief Ingredient in their Nutriment, and by consequence of their Generation) a little altered from its first Complexion: And that the reason why Animals that feed on Vegetables are obliged by Nature to longer meals than those that feed on other Animals, is, because Animals are fuller of that Salt than Vegetables: And indeed such Animals are but Caterers of it for Man; Rh