MORBID POISONS. 353 



pound B, which is to be reproduced ; and if this 

 second body be oxalic acid dissolved in water, then 

 the following changes are observed to take place : 

 The oxamide is decomposed by the oxalic acid, 

 provided the conditions necessary for their exercis- 

 ing an action upon one another are present. The 

 elements of water unite with the constituents of 

 oxamide, and ammonia is one product formed, and 

 oxalic acid the other, both in exactly the proper 

 proportions to combine and form a neutral salt. 



Here the contact of oxamide and oxalic acid in- 

 duces a transformation of the oxamide, which is de- 

 composed into oxalic acid and ammonia. The oxalic 

 acid thus formed, as well as that originally added, 

 are shared by the ammonia or in other words, as 

 much free oxalic acid exists after the decomposi- 

 tion as before it, and is of course still possessed of 

 its original power. It matters not whether the free 

 oxalic acid is that originally added, or that newly 

 produced ; it is certain that it has been reproduced 

 in an equal quantity by the decomposition. 



If we now add to the same mixture a fresh por- 

 tion of oxamide, exactly equal in quantity to that 

 first used, and treat it in the same manner, the 

 same decomposition is repeated ; the free oxalic 

 acid enters into combination, whilst another portion 

 is liberated. In this manner a very minute quan- 

 tity of oxalic acid may be made to effect the de- 

 composition of several hundred pounds of oxamide ; 



A A 



