Hooke Folio
zoom inzoom outrestorefirstlastpreviousnextimagetranscriptHome

Loading Image

© The Royal Society

303

march . 20 . 1678/9.


mr. Henshaw the vice President tooke the chair.
The minutes of march the 13th. were read which gaue occa
sion to Discourse concerning the Ingredients of Gunpowder
mr. Hooke conceiued that one great cause of the sudden Ex
pansion of the powders was the operation of the Alcalizate
salt in the Cole that serued to compound the powder
Sr. Iohn Hoskins doubted this supposition conception querying
by wt. meanes we were assured of the being of Alcalj in Cole
And whether It could be thence extracted wthout actually re
ducing it to ashes. To wch. It was answered ^ /by mr. Hooke/ that though pos
sibly It could not be actually extracted in the forme of an
alcalj salt, yet that it did produce its Effects as much as
if it were Reduced witnesse the effects it hath vpon Iron
& copper to Reduce them into steel & Brasse. Besides that
the effect thereof seems manifestly to be the very same wth the
Alcalj in the Puluis Fulminans, which is made of niter
and sulphur in the same proportions as in Gunpowder
and Differs only from it, in hauing an alcalizate salt -
mixed wth the other ingredients insteed of powder of charcole
And that the sudden expansion in each of them was occasioned by
the salts working one vpon the other in the way of Dissolution
that Descartes Hypothesis of the turbinated motion of the nitrous
parts was not sufficient for the effect; nor was their any grou[nd]
to suppose beleiue such a motion. Sr. Iohn Hoskins vrged that
as there was very little acalj to be extracted out of cole a
small quantity of cole any way, and soe twas not likely to be the
cause of soe great an effect, soe that euen of that wch. was
a great part of it would be left behind after the Gunpowder
was fired in a musket Barrell or the like, soe that It should
Rather seem that the Alcalizate part were vselesse & insignifi
cant It being none of the parts flew aw that expand & fly away