on the fpecific Gravities, &c. of Saline Subfiances. 189 
lution wanted of being equal to the joint weights of the water, 
alkali, and fpirit of vitriol employed. 
The quantity of mere vitriolic acid neceflary to faturate 
100 gr. of pure mineral alkali I found to be 60 or 61 gr. the 
faturated folution, thus formed, being evaporated to perfed 
drynefs weighed 36,5 gr. ; but of this weight only 28,38 were 
alkali and acid, therefore the remainder, that is, 8,12 gr. were 
water. Hence, 100 gr. of Glauber’s fait, perfedly dried, 
contain 29,12 of mere vitriolic acid, 48,6 of mere alkali, 
and 22,28 of water; but Glauber’s fait cryftallized contains 
a much larger proportion of water; for 100 gr. of thefe cry- 
ftals being heated red-hot loft 55 gr. of their weight. This 
lofs I fuppofe to arife merely from the evaporation of the wa- 
tery part, and the remaining 45 contained alkali,, water, and 
acid, in the fame proportion as the 100 gr. of Glauber’s fait,, 
perfectly dried, abovemen tioned ; then thefe 45 contained 13,19 
gr. of vitriolic acid, 21,87 of fixed alkali, and 9,94 of water; 
confequently 100 gr. of cryftallized' Glauber’s fait contain 
13,19 of vitriolic acid, 21,87 of alkali, 311^64,94 of water. 
I alfo faturated this alkali with the dephlogifticated nitrous 
acid, and found that 100 gr. of the alkali took up 57 of the 
mere nitrous acid in the experiment I moft depended on ; but 
this quantity varied in; fome experiments a few grains, being 
fometimes 60, and fometimes 63 gr. ; fo that 1 conclude the 
proportion of this acid, taken up by the alkali, is nearly the 
fame as that of the vitriolic acid. Suppoling this quantity to 
be 57 gr. then 100 gr. Cubic nitre, perfedly dry, contain 30 
of acid, 52,18 of alkali, and 17,82 of water; but. Cubic nitre 
cryftallized contains fomething more water; for 100 gr. of 
thefe cryftals lole about 4 by gentle drying; therefore too gr. 
of 
