and attractive Powers of various j aline Subfiances , 33 
It is harder to find the point of faturation with the vegetable 
than with the mineral acids ; becanfe they contain a mucilage 
that prevents their immediate union with alkalies, and hence 
they are commonly ufed in too great quantity. They fhould 
be ufed moderately hot, and fufficient time allowed them to 
unite. 
From thefe experiments it follows : 
1 ft. That fixed vegetable alkalies take up an equal quantity of 
the three mineral acids, and probably of all pure acids ; for we 
have feen, that 8,3 grains of pure vegetable alkali (that is, free 
from fixed air) take up 3,55 gr. of each of thefe acids, and con- 
fequently 100 parts of cauftic fixed alkali would require 42,4 
parts of acid to faturate them. Now, Mr. bergman has 
found, that 100 parts of cauftic fixed vegetable alkali take up 
47 parts of the aerial acid, which, confidering his alkali might 
contain fome water, differs but little from my calculation. It 
ftipuld therefore feem, that alkalies have a certain determinate 
capacity of uniting to acids, that is, to a given weight of acids ; 
and that this capacity is equally fatiated by that given weight 
of any pure acid indifcriminately. This weight is about 2,35 
of the weight of the vegetable alkali. 
2dly. That the three mineral acids, and probably all pure 
acids, take up 2,253 ti mes their own weight of pure vegetable 
alkali, that is, are faturated by that quantity. 
3dly. That the denfity accruing to compound fubftances 
from the union of their component parts, and exceeding its 
mathematical ratio, increafes from a minimum, when the quan- 
tity of one of them is very fmall in proportion to that of the 
other, to a maximum , when their quantities differ lefs ; but 
that the attraction, on the contrary, of that part which is in 
the fmalleft quantity to that which is in the greater, is at its 
Vol. LXXI. F maximum 
