vegetable and animal substances. 4 79 
Of crystalline citric acid, the prime equivalent is 8.375 by 
my experiments ; and it consists probably of 
Carbon 4 atoms 
. . 3.000 . 
• 35-8 
Hydrogen 3 
. . 0.375 . 
• 4-5 
Oxygen 5 
. 5.000 . 
• 59-7 
8-375 
100.0 
or, of 4 atoms carbon, 3 
water, and 2 oxygen. 2 of these 
atoms of water are separated, when citric 
acid is combined 
with oxide of lead in what 
is called the dry citrate. Hence, 
the acid atom is in this case 6.125. 
The prime equivalent of 
crystalline tartaric acid is 9.25 by 
my results ; and it seems made up of 
Carbon 4 atoms 
. . 3.0 . 
• 3243 
Hydrogen 2 
. 0.25 
. 2.70 
Oxygen 6 
. . 6.00 . 
. 64.87 
9- 2 5 
100.00 
or, of Carbon 4 atoms 
. . 3.0 . 
32.43 
Oxygen 4 
. 4.0 . 
. 43.24 
Water 2 
. . 2.25 
• 2433 
9' 2 5 
100.00 
From my experiments I have been led to conclude, that 
into dry tartrate of lead these two atoms of water do enter 
as a constituent ; and, hence, that the crystals of tartaric acid 
are as dry as is compatible with its constitution. 
Oxalic acid crystals have 7.875 for their prime equivalent ; 
and are composed of 
Carbon 2 atoms . . 1.500 . . 19.04 
Hydrogen 3 . . 0.375 . . 4.80 
Oxygen 6 . . 6.000 . . 76.16 
7-875 
100.00 
