AMMONIACAL SALTS. 335 



$alt may be now restricted to the carbonate alone. At least, having 

 watered young plants of trefoil, growr, in silicious sand, with solu- 

 tion of oxalate of ammonia at ir^TT^h* 1 observed them die after the 

 lapse of eight or ten days. Plants of the same size, sown under 

 like conditions, but irrigated with distilled water, continued to grow 

 and flowered. 



In treating of gypsing, I have assigned my reasons against admit- 

 ting that the azote fixed during the culture of trefoil, proceeds from 

 the sulphate or muriate of ammonia naturally absorbed. I again 

 assert, that it is materially impossible that ammoniacal salts com- 

 bined with inorganic acids, other than the carbonic, can be usefui as 

 manure to plants, when administered separately ; they can only be- 

 come advantageous when their composition has undergone modifica- 

 tion. 



.Two cwt. (220 lbs.) of wheat-sheaves, (straw and grain,) contain 

 upon an average 2 lbs. 1 oz. 14 dwts. of azote, and leave after igni- 

 tion 11 lbs. 3 oz. 16 dwts. of ash, into which enter 1 oz. 7 dwts. of 

 sulphuric acid, and 14 dwts. of chlorine. 



In the ammoniacal salts : 



100 of azote corresponds to 283 of sulphuric acid. 

 " " 257 of chlorine. 



Let us now consider sulphate of ammonia, which, according to the 

 experiments of M. Schattenmann, supplied an excellent manure for 

 wheat. If the 2 lbs. 1 oz. 14 dwts. of azote contained in the 2 cwt. 

 of sheaves be derived from the sulphate absorbed by the cereal, the 

 sulphuric acid of the sulphate ought to be recovered in its ashes ; 

 and according to the above standard, these ashes ought to contain 

 6 lbs. 16 dwts. of sulphuric acid. They afforded by analysis only 



1 oz. 7 dwts. 



Applying the same reasoning to muriate of ammonia, we find, 



supposing the azote of the 2 cwt. of sheaves to emanate from this 

 salt, that the ashes should contain 5 lbs. 6 oz. 2 dwts. of chlorine ; 

 whereas they really contain but 14 dwts. 



Without doubt, the nitrogenous principles of the cereal cannot be re- 

 ferred solely to the ammoniacal salts in the trials of M. Schattenmann; 

 the manure given to the soil, and the atmosphere must have contribu- 

 ted a share. The appreciation of the value of ammoniacal salts be- 

 comes more precise when the results obtained on meadow land are 

 estimated. There the produce was doubled, and of every 2 cwt. ol 

 hay gathered, 1 cwt. may be ascribed to the action of the salt. 



Two cwt. of hay, containing 4 lbs. 16 dwts. of azote, leave 16 lbs, 



2 oz. of ash. 



If the half (2 lbs. 8 dwts.) of the azote of the fodder comes from 

 the ammoniacal salts, the ashes will contain : 



lb». oz. dwu. 



5 8 4 of sulphuric acid, if the sulphate has been naed, 



5 2 ■' " ifth? mtuiate has been " 



Now, the ashes of the hay yielded by analysis : 



OS. dwu. 



5 9 of sulphuric acid. 



S 4 ofchlorins. 



