272 



APPENDIX TO PART I. 



nitrate of soda, gives a profit of 2Z. lis. 2d. per acre, after 

 deducting I/. 3s. Od. for the value of the salt employed. 



*'But not only does the nitrate increase the quantity of 

 the grain, but it tends to augment those ingredients, which 

 contain the largest amount of nitrogen, and consequently 

 afford the greatest degree of nutriment, namely, the gluten 

 and albumen. 



**This is shown, by the analysis of the nitrated, and non- 

 nitrated wheat, made by a chemist at his request, the re- 

 suits of which were as follows : 



** Thus it is seen, that in the nitrated wheat there was 

 4'25 per cent, more gluten, and 0*75 more albumen, than 

 in the non-nitrated sample. 



'* Considering, then, that these constituents contain nearly 

 16 per cent, of nitrogen, we are justified perhaps in at- 

 tributing their increase to the decomposition of the nitric 

 acid present in the salt, and the consequent supply of nitro- 

 gen in greater abundance than is naturally present in the 

 soil. 



*' And if such be the mode of its operation, it may be 

 possible to explain why these salts should appear so capri- 

 cious in their effects on the different kinds of land to which 

 they have been applied. 



'' When the ground already contains all the other con- 

 stituents which the plant requires, as, for instance, a suffi- 

 cient amount of the earthy phosphates, and of silicate of 

 potass, the addition of the nitric salt will do good, by sup- 

 plying nitrogen, and thus enabling the vegetable to assimi- 

 late a proportionate quantity of the other ingredients. 



"But when the latter are already nearly exhausted, the 

 addition of the nitrates will no Jonger be of advantage, 

 since only that portion of nitrogen can be assimilated 

 which is equivalent to the amount of the earthy phosphates, 

 of the silicate of potass, and of the other fixed ingredients, 

 which the plant obtains from the soil. 



