and attractive Pozvers of various Jaline Subjlances. i 5 
Thus, in this cafe, 1,098 - 1,000 = ,098 is the magnitude 
of the heavier ingredient, viz* the marine acid ; and, 098 x 
3,100 = 0,3038 the weight of the marine acid; and, on the 
other hand, 3,100-1,098=2,002 the magnitude of the wa- 
ter, and 2,oo 2 x 1,000=2,002 its weight; the fum of thefe 
weights is 2,3058 : then, if 2,3058 parts of fpirit of fait con- 
tain 0,3038 parts acid, 27 gr. of this fpirit of fait will contain 
3,55 acid. 
In the fame manner it will be found, that 23,35 gr. of fpirit 
of fait,, whofe fpecific gravity was 1,^15, contained 3,55 gr,. 
acid* 
The point of faturation was pretty accurately found by put- 
ting the glafs cylinder which contained the alkaline folution on 
the fcale of a very fenfible balance, and at the fame time weigh- 
ing the acid liquor in another pair of fcales, when the lofs of 
weight indicated the efcape of nearly equal quantities of the 
fixed air contained in the folution ; then the acid was gradually 
added, by dipping a glafs rod into it, to the top of which x 
fmall drop of acid adhered : with this the folution was ftirred* 
and very fmall drops taken up and laid on bits of paper flamed 
blue with radfth juice. As foon as the paper was in the leaft 
reddened, the operation was completed fo that there was always 
a very fmall excefs of acid, for which half a grain was con- 
ftantly allowed ; but no allowance was made for the fixed air* 
which always remains in the folution ; but as, on this account* 
only a fmall quantity of the alkaline folution was ufed, this 
proportion of fixed air muft have been inconfiderable. If an 
ounce of the folution had been employed, this inappreciable 
portion of fixed air would be fufficient to caufe a fenfible error : 
for I judged of the quantity of fixed air loft by the difference 
betwixt the Weight added to the 100 gr. and the a&ual weight 
