SPECIFIC GRAVITY AND NITROGEN CONTENT. 39 



In the light of the experiments that have been conducted with 

 seed wheat of high and low specific gravities, it would appear that, 

 in general, seed of very low specific gravity does not yield well, and 

 it is evident that such seed must be deficient in mineral matter and 

 is probably not normal in other respects. There would not appear, 

 however, to be any marked difference in the productive capacity of 

 kernels of medium specific gravity and kernels of great specific 

 gravity. 



RELATION OF SPECIFIC GRAVITY OF KERNEL TO NITROGEN CONTENT. 



Murek" found that with an increase in the specific gravity of the 

 kernel there was a decrease in nitrogen content. 



Pagnoul, 6 in testing seventy varieties of wheat, found that the 

 nitrogen content rose with the specific gravity, but not regularly, 

 and that a definite relation could not be traced. 



Wollny took kernels of horny structure and kernels of mealy 

 structure. He says it is generally recognized that the hard, horny 

 kernels have a higher specific gravity, and that it is commonly 

 attributed to their higher content of proteids. He contends that as 

 starch has a higher specific gravity than protein the mealy kernels 

 must really have a higher specific gravity than the horny ones. 



Kornicke and Werner'' state the specific gravities of the various 

 chemical constituents of the wheat kernel as follows: Starch, 1.53; 

 sugar, 1.60; cellulose, 1.53; fats, 0.91 to 0.96; gluten, 1.297; ash, 

 2.50; water, 1.00; air, 0.001293. They state also (p. 121) that the 

 specific gravity of the kernel does not stand in any relation to the 

 volume weight, for the factor which results from weighing a certain 

 volume mass is influenced by the air spaces between the kernels, and 

 these depend upon the form and size as well as the surface and acci- 

 dental structure of the kernel. They also contend that there is no 

 relation between the volume weight and the content of proteid 

 material. 



Schindler* shows that by tabulating a large number of varieties 

 of wheat from different parts of the world, and representing different 

 varieties, there is no relation between the weight of 1,000 kernels 

 and the volume weight of 100 c. c. By separating these into varieties,, 

 even when grown in different localities, kernels of the same variety 

 did show a definite and constant relation. The volume weight 

 increased with an increase in the w r eight of 1,000 kernels. 



Abstract in Centrlb. f. Agr. Chem., 1876, p. 46, from Landw. Zeitung f. Westfalen u. 

 Lippe, 1875, p. 362. 



' Abstract in Centrlb. f. Agr. Chem., 1888, p. 767, from Ann. Agron., 14, ppr262-272. 



f Abstract in Centrlb. f. Agr. Chem., 1887, p. 169, from Forschungen a. d. Gebiete Agri- 

 kulturphysik, 9 (1886), pp. 207-216. 



11 Handbuch des Getreidebaues, 2, p. 120, Berlin, 1884. 



' Jour. Landw., 45 (1897), p. 61. 



