0,1 Oxalic Acid, 249 



which reduced to 100 parts, becomes 



Oxygen 49" 27 



Carbon 42-95 

 IJvdrocren 7'78 



100-00 



5. The residue which reniained in the retort, after the 

 distillation w'as over, was a gray powder, not unlike pound- 

 ed clay slate. To ascertain its constituents, it was dissolved 

 in diluted nitric acid with the necessary precautions ; the 

 loss of weight indicated the quantity of carbonic acid. The 

 charcoal remaining undissolved, was allowed to subside, 

 gareFulty washed by repealed affusions of water, and then 

 drfed in a glass or porcelain capsule. It must not be sepa- 

 rated by the filter, for it adheres so obstinately that it can- 

 not be taken off the paper, nor weighed. The nitric acid 

 solution was precipitated by carbonate of soda, and the car- 

 bonate of lime obtained was violently heated in a platinum 

 crucible. What remained was pure lime. 



6. I shall now detail one of my experiments more parti- 

 cularly. Eighty-nine grains of well dried oxalate of lime 

 were exposed in a small retort to a heat gradually raised to 

 jcdness; the products were the following: 



Grains. 



4.5-6 cubic inches of gas* weisrhinof 14-8 

 Water - ""- "- 6-4 



Residue in retort - - 62-4 



S3-G 

 J^oss - - - 5-4 



Total S9-0 



The loss is obviously owing to the gas which fdled the retort 

 and tube when the experiment was concluded. We are 

 warranted therefore to add it to the weight of the gaseous 

 products obtained. 



• The gas obtained measured 60 cubic inches, but 14 4 inches of these 

 were found to be common air which had previously filled the retort and 

 tube; tliis quantity was therefore (^cductcd. 



Now 



