in Agriculture. 181 



Table of Constituents calculated to 100 parts of the dry salt. 



Since the ammonia which occurs in nature, whether eliminated 

 directly from decaying organic matters, or existing as atmospheric 

 ammonia, is invariably in the immediate presence of an enormous 

 excess of carbonic acid, we may safely conclude that it is always 

 in the state of carbonate; and as, on the one hand, it is brought 

 down to the earth from the atmospheric regions dissolved in rain 

 or dew, and, on the other, when met with in the salt itself, is 

 usually in the presence of abundance of moisture, we may infer 

 that the carbonate of ammonia is presented to absorbent agents 

 in the soil for the most part in a state of solution. I do not 

 think, therefore, that any great departure from the natural course 

 of things can be alleged against the following experiments, which 

 have been made with a solution of the commercial so-called ses- 

 quicarbonate of ammonia, containing 4-3 per cent, of ammonia 

 (NH''0). 



Taking, then, these specimens of agricultural salt in the state 

 in -vvhich they are supplied at the salt works, the first thing was 

 to ascertain whether any absorption occurred upon mi.\ing them 

 in that condition with this solution of carbonate of ammonia. 

 Quantities of from 2 to 3 ozs. of the salts were placed in wide- 

 mouthed bottlco, and small quantities of the standard ammonia 

 solution added, containing an absolute amount of anmionia ( N H^Q) 

 varj'ing from -15 to -04 of a grain. The contents of the bottle 

 were shaken together, and an extremely delicate red litmus-paper 

 inserted ; it was completely blued in a minute or two ; and as the 

 same action took place after allowing the salt and ammonia solu- 

 tion to remain all night in contact, the fact that no absorption 



