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inclination as I have, more fully to carry out this investigation, 

 A recent indisposition having lately confined me in a great 

 measure to the house, I have had leisure to make several ex- 

 periments, the result of which I will proceed to detail. It is 

 well known that in all animal and vegetable substances which 

 are used as manure, the ammonia which is generated by their 

 putrefaction is the most essential and valuable part, and is, at 

 the same time, the most difficult to preserve. In fact, the 

 farmer who, ignorant of this truth, endeavours to increase the 

 value of the contents of his farm-yard by frequently turning 

 it, retains a hody without the spirit, and dissipates into the air 

 the ammonia, which, as containing nitrogen, is so essential a 

 constituent of his future crop. The ammonia generated by 

 fermentation becomes almost immediately carbonate of am- 

 monia, and in this state still remains extremely volatile; 

 common smelling salts sufficiently attest this fact. It may, 

 however, be imagined that ammonia so generated does not 

 escape into the air to any considerable degree, but is retained 

 in the body of the manure. I can, however, bring forward 

 a circumstance that has come to my knowledge, which I think 

 may fairly be adduced as a proof that the escape of this 

 important fertilizer is greater than is generally supposed. In 

 the neighbourhood of Wakefield there are some chemical 

 works, where soda is prepared from common salt: during the 

 process employed, the muriatic acid (one of the component 

 parts of salt) is driven off into the air in the state of vapour, 

 which, by the bye, is an extremely wasteful and deleterious 

 proceeding. It was observed by the workmen that when the 

 wind was in one particular quarter, and carried this vapour 

 over a field where a large manure heap was deposited, a thick 

 white cloud always hung over it. This cloud was caused by 

 the escaping ammonia combining with the muriatic acid, and 

 forming muriate of ammonia, or sal ammoniac, in finely divided 

 particles. 



K 2 



