£o Mr. Henry on the Vrefdrvatlon 
to which it is reduced by calcination, viz. void 
of fixed air. In this ftate, I have formerly 
proved, by a train of experiments, that it is 
ftrongly antifeptic. * Being infoluble, the water 
is preferved without forming any combination 
with it 5 and the only alteration that is made in 
the component parts of the lea water, is, that the 
earthy marine fait changes its bafis of magnefia 
for one that is calcareous. 
We alfo fee, that there are limits to the addition 
of quicklime, beyond which, we cannot proceed, 
without forming lime water. The quantity of 
two fcruples, to a quart of fea water, though not 
fufficient to decompofe the whole of the magnefian 
fait, was yet adequate to the prefervation of the 
water. One drachm more of quicklime feparated 
the whole of the magnefia, and, when a further 
addition was made, a lime water was immediately 
formed, f 
The properties of common fait, as an antifeptic, 
are greatly weakened by the portion of marine 
* From thefe experiments it appeared, that magnefia 
alba, while pofieifed of its fixed air, is highly feptic to 
animal fiefii, but antifeptic to bile ; whereas, when cal¬ 
cined, and deprived of its fixed air, it is ftrongly anti¬ 
feptic both to flefh and bile. 
See Henry’s Experiments and Obfervations, 
p. 58. & feq. 
F Thefe proportions may vary, according to the ftrength 
of the quicklime employed. 
, niagnefian 
