518 



Liebig having proved in his work on Agricultural Che- 

 mistry that the nitrogenous compounds of vegetables are de- 

 rived principally from the decomposition of ammonia, and 

 that the carbon is derived from the carbonic acid of the at- 

 mosphere, it occurred to me to try (while experimenting on 

 some manures) whether a source of each might not be found 

 in some salt of cyanogen (C2 n). This, I think, the following 

 facts will make probable. The salt I used for this purpose 

 was the ferro-cyanuret of potassium, 



(KaCfy = C6N3 + Fe + K^. 



EXPERIMENTS. 



A piece of grass was selected in the garden, as being as 

 even and equal as possible, and five plots were marked out 

 on it, side by side, each containing exactly ten square yards ; 

 they were marked out by pegs in the corners, and a line put 

 round each while the salts were putting on, and during the 

 cutting of the grass. They were then manured as follows, 

 on the 17th of June last: 

 No. 1. Muriate of Ammonia, 3 oz. 



2. Aqua Ammonia of the shops, \ a pint ; with Linseed 



Oil, 4 pints. 



3. Nothing. 



4. Yellow Prussiate of Potash, 3 oz. In the usual state, 



as sold by druggists, in crystals, 

 /■phosphate of Soda, 1| oz. 

 J Pearl Ash, 3 oz. 

 ' ] Sulphate of Magnesia, 1 1 oz. 

 V Carbonate of Ammonia, 3 oz. 

 The salts on these two last plots were not laid on till the 

 26th of June, which gave them a shght disadvantage. They 

 were all mown on the 25th of September, and weighed fresh 

 the moment they were cut, when the weights were as fol- 

 lows : 



