Dr. Thomson on Oxalic Acid. 
67 
Though the oxalate oflime dried spontaneously can scarcely 
be considered as always in the same state, yet as the differ- 
ence in the portion of water which ft retains is not great, pro- 
vided it be dried slowly in the temperature of 6o°, and in a 
dry place, it may be worth while to state its composition. It 
is as follows : 
Acid 45 or per cent. 59.2 acid. 
Base 27 35.5 base. 
Water 4 5.3 water. 
7 6 100.0 
When rapidly dried, as by pressing it between the folds of 
filtering paper, it is apt to concrete into hard lumps, which 
retain more moisture. In this state I have sometimes seen it 
retain 10 per cent, of water after it appeared dry. 
Bergmann states the composition of oxalate of lime as 
follows : 
Acid - 48 
Lime - -4 6 
Water - - 6 
100* 
His method was to dissolve a determinate quantity of cal- 
careous spar in nitric acid, and then to precipitate the lime by 
oxalic acid. 100 parts of calcareous spar thus dissolved, re- 
quire, according to him, 82 parts of crystallized acid to pre- 
cipitate them. But there must have been some mistake in this 
experiment ; for, according to my trials ( provided the nitric 
acid be carefully neutralized by ammonia as it is evolved), no 
* Opusc. I. 262, 
K 2 
K 
