236 



On Agricultural Chemistry. 



That the gluten and albumen in wheat would increase in pro- 

 portion to the richness of the soil and to the amount of nitrogen 

 and ammonia supplied in the manure seems so reasonable a sup- 

 position that its correctness is admitted without dispute ; and 

 various experiments have been tried which appear to favour this 

 opinion. Boussingault, in his ' Rural Economy,' says, that wheat 

 planted in an open field gave 2 • 29 per cent, of nitrogen, equiva- 

 lent to 14 '31 per cent, of gluten and albumen, while that planted 

 in a rich garden-soil gave 3*51 of nitrogen, or 2 1 • 94 of gluten 

 and albumen ; and Hermstadt obtained from wheat grown — 



In a soil unmatured . . .9 per cent of gluten. 

 In a soil manured with cow-dung . 12 ditto. 



sheep ditto . 22-9 ditto. 



, , bullock's blood 35 ditto. 



, , urine . . 36 ditto. 



It is not stated how the gluten and albumen were determined, 

 but it is not improbable that some mechanical process was em- 

 ployed ; at all events, I have great doubts about the accuracy or 

 the completeness of the experiments. Thirty-five per cent, of 

 gluten would be equivalent to nearly 6 per cent, of nitrogen, a 

 quantity certainly greater than wheat ever contains. My own ex- 

 periments do not give the slightest indication of an increase of 

 nitrogenous element of wheat grain by the employment of 

 ammoniacal manures. That the average produce of nitrogen in the 

 crop bears a certain relation to the ammonia supplied in the 

 manure is very evident ; but the per centage of nitrogen in the 

 grain cannot be increased by means of it. In some experiments, 

 the quantity of ammonia supplied by the manures was from 60 

 to 70 lbs. per acre, and in some instances more; but the analyses 

 give no evidence of an increased per centage of nitrogen by its 

 supply, and the highest amount obtained in the series was from 

 an experiment where no ammonia was supplied in the manure. 

 Dr. R. D. Thomson, in his Experimental Researches on the 

 Food of Animals," says, ^' It is a sufficiently remarkable fact, that 

 oats increase in nutritive power in proportion to the increase of 

 latitude within certain limits, while wheat follows an inverse law." 

 He seems here to have adopted the prevailing opinion that the 

 finest descriptions of wheat contain the most nourishment. The 

 oat, which is capable of thriving in a moister and colder climate 

 than either wheat or barley, would undoubtedly contain more 

 nourishment when grown in high latitudes, simply because the 

 climate is not favourable to the production of the important car- 

 bonaceous compound of gramineous seeds, starch. But with the 

 most favourable condition of soil and climate the grain-producing 

 plants are undoubtedly governed by one and the same law. A\- 



