PRACTICAL INFERENCES. 275 



3 had produced 4 lbs. 4 ozs. of bread, in No. 2. produced 



4 lbs. 14 ozs. Now 



*' As 4 lbs. 4 ozs. : 4 lbs. 14 ozs. : : 100 : 1 14. 



'* Showing an increase per cent, of 14 -f- 20 = 34 per 

 cent. 



''Now if we calculate the wheat as worth eight shillings 

 a bushel, the profit of using the nitrate of potass will stand 

 as follows : 



''27 bushels 36 lbs. at 8.s. = 1IZ. value of the produce on 

 the non-nitrated land : add 34 per cent, or Jrd = 3/. 135. 

 4d., for the value of the nitrated, which, after deducting 

 1/. \0s. for the value of a cwt. of nitrate of potass, and for 

 carriage, will leave to the farmer a clear profit of 2/. 3s. 4d. 



" The superior absorbing power of the nitrated flour, 

 over the non-nitrated, was found to depend upon the pres- 

 ence of a larger amount of gluten, for I discovered in the 

 former 740 grs. in the pound, or 13 per cent. ; in the latter 

 850 grs. in the pound, or 15 per cent, of that ingredient, 

 the difference being 2 per cent, in favor of the nitrated 

 wheat, a result which confirms, in a very satisfactory man- 

 ner, the statement of Mr. Hyett.^ 



"But how are we to account for the failure of the nitrate 

 of soda, on soil which had been so materially benefited by 

 the administration of nitrate of potass .^ 



"The small scale upon which the experiment was 

 conducted, may render us reluctant to build much upon 

 the results obtained, until it has been again repeated, but 

 supposing the fact to be hereafter confirmed, I can only 

 conjecture, that the difference must have arisen from a 

 deficiency in the land, of potass, which would be supplied 

 by the saltpetre, but not by the nitrate of soda. | Should 

 this be the true solution, those soils, in which nitrate of soda 

 has succeeded, ought to contain a larger quantity of potass, 

 than those in which it has failed. 



"The general principles laid down may also inform us, 

 as to the true plan upon which the succession of our crops 

 should be regulated. 



" Those plants ought to succeed each other, which con- 

 tain different chemical ingredients, so that the quantities 



" * The amount of gluten is smaller than in the samples reported on 

 by Mr. Hyett, but my gluten was dried, with the greatest care, under 

 the exhausted receiver of an air-pump, with sulphuric acid, till it 

 ceased to lose weight." 



" t Nitrate of soda is stated to exist in barley, but it has not been de- 

 tected in wheat. It would therefore be worth while to see, whether 

 the above salt is particularly suited to the former crop.'* 



