STATISTICS Oi 1 WHEAT CULTURE, 235 



In the fourteen samples which lie analysed, the proportion of water ranges from 

 13.2 to 15.2, which is a rather higher average than is yielded by our American 

 samples, especially those whifh have not been shipped across the Atlantic. Of 

 the nitrogenous matter, soluble and insoluble, the proportions range from 9.90 

 per cent, to 21.50 per cent. ; the former being from a sample of very soft and 

 white French wheat ; the latter from a very hard wheat with long grains, from 

 Northern Africa, cultivated at Verrieres. Another sample from Egypt yielded 

 20.60 per cent, of these nitrogenous matters, both of which are very remarkable 

 proportions. 



In describing the process for ascertaining the amount of insoluble nitrogenous 

 matters, this author adverts to their estimation either by the quantity of nitro- 

 gen gas furnished, or of ammonia formed, the last being preferred for substances, 

 which, like wheat, contain only a few hundredths of nitrogen. The results 

 which ho obtained by this method were compared with those yielded by the 

 direct extraction of the gluten by softening the farina under a small stream of 

 water. "These results," says he, " differ but little from each other when we 

 operate upon wheat in good condition, although the gluten which we thus ob- 

 tain holds some starch and fatty matter, while the starch which is carried away 

 by the water contains also some gluten." The loss and gain, as I have already 

 explained, and as has been proved by these and other comparisons, are nearly 

 balanced, and the amount of rough gluten will therefore afford a fair exhibit of 

 that of the insoluble nitrogenous matters in this grain. 



The salts in the samples of wheat analysed by M. Peligot, were either want- 

 ing or were in small proportion ; while the amount of fatty matter ranged 

 from 1-00 to 1'80 and 1'90 per cent. 



These results agree very well with those which I have obtained. But it is 

 probable that the proportion is liable to great variation, inasmuch as it is in- 

 ferred that the fatty matter originates from starch through its exposure to the 

 general deoxidising influence which prevails in plants * 



There are also many difficulties attending the acciirate determination of this 

 matter, and which are probably the cause of the higher proportion often given. 

 It is properly remarked by M. Peligot that the ether employed in this process 

 should be free from water, and that the flour ought also to be very dry. By 

 neglecting these precautions, we separate not only the fatty matter, but also a 

 certain amount of matters soluble in the water, which is furnished as well by 

 the wheat as by the ether. 



It would not, I think, be difficult to point out some incorrect views enter- 

 tained by this chemist, and more especially those which relate to the fatty 

 matter. Some of his processes for the separation of various substances, if not 

 faulty, require so many conditions for success as to render the results, at least 

 in other hands, exceedingly uncertain. 



But the capital error which he has committed is- that concerning the bran, 

 already adverted to, which he considers injurious to the flour, chiefly in con- 

 sequence of the large proportion of fatty matter which it contains. 



In regard to the soluble nitrogenous matter usually called albumen, from its 

 resemblance to the animal substance of the same name, I have to remark that 

 in my trials the proportion has been found to be considerably less than that 

 often given in tables of the composition of wheat. In one sample it was 

 found to be as low as 0'15 per cant., in another it did not rise above 0'20 per 

 cent. The amount was usually so inconsiderable, that I did not think it worth 

 while to retard the progress of the work by following out processes which, 

 could add little to the utility of these investigations. 



Although much time and labor have been expended upon the analyses of the 

 ash of plants, I have but slight confidence in the results heretofore given. The 

 difficulties which attend the obtaining the ash in a proper condition, and the 

 fact that the products of all the organs and parts of the plants have been 

 analysed together, must necessarily impair the accuracy of the experiments, 

 and render the inferences drawn from them of uncertain value. Much, indeed 

 I may say almost everything, still remains to be done in this department of 

 agricultural chemistry. 



* Mulder's Chemistry of Vegetable and Animal Physiology English Translation, p. 816. 



