102 COMBUSTIBLE ACIDS. 



is evident, that the oxalic acid in 9 grains of the 

 crystals just saturates all the lime in 6*5 grains 

 of calcareous spar; but it has been already 

 shown that the quantity of lime in 6*25 grains 

 of the carbonate is 3*5 grains, which is equiva- 

 lent to the atom of lime. As the oxalate of 

 lime formed is quite neutral, the oxalic acid 

 united to the lime must be equivalent to an atom 

 of that acid. Thus it appears, that 9 of the crys- 

 tallized acid is the equivalent for an atom of the 

 acid. 



2. The oxalate of lime, formed in the preced- 

 ing experiment, was collected on a double filter, 

 and after being well washed with distilled water, 

 was dried in a temperature between 90 and 

 100 ; its weight was 10-25 grains. Being kept 

 for some hours in the temperature of 560, its 

 weight was reduced to 8 grains, and it still pos- 

 sessed all the characters of oxalate of lime. Now, 

 3 '5 grains of the salt were lime ; hence, the 

 weight of the oxalic acid necessary to saturate 



Atomic an atom of lime is 8 3%5 = 4%5. And, since 

 the salt, is neutral, 4%5 must be the weight of an 

 atom of oxalic acid. 



3. The 4%5 grains constituted the quantity 

 of real oxalic acid in 9 grains of the crystals. 

 The rest of the weight must consist of water. 

 Consequently, oxalic acid crystals are composed 

 of 



