12 STUDIES OF AMERICAN BARLEYS AND MALTS. 



mealy and a glassy wheat was due to the small air spare- imprisoned 

 between the starch granules of the mealy grains and that the specific 

 gravity of the mealy grains was less than that of the flinty. Munro 

 and Beaven likewise showed that, the specific gravity of mealy ker- 

 nels is less, due to the larger amount of interstitial air, and that 

 the nitrogen content of such grains is lower, in consequence of which 

 they modify better than do the steely grains. Groenlund b called 

 attention to the fact that when glassy kernels are steeped and then 

 dried some of the grains become mellow while others remain un- 

 changed. This procedure distinguishes between apparent and real 

 glassiness, and upon this fact Prior b bases his method for the determi- 

 nation of the degree of dissolution of barley, which consists of the 

 sum of the mealy grains originally present and the percentage of 

 steely grains which become mealy on steeping. This factor shows 

 that the higher the protein content the lower, as a rule, is the degree 

 of dissolution. A later contribution by Prior c called attention for 

 the first time to the role played by the variety of barley on this 

 determination; that what was true of one variety was not neces- 

 sarily so of another; that is, in some varieties the steely grains are 

 more easily modified than in others. H. T. Brown & likewise devel- 

 oped a method for the estimation of the coefficient of mealiness, results 

 of which give indication to a certain extent of the value of a barley 

 for brewing or feeding purposes, as he finds that a high coefficient 

 of mealiness is generally accompanied by a low protein content, or 

 vice versa. 



Jalowetz 6 investigated the relation between the protein content 

 and the character of the endosperm and agreed with other authors 

 that mealy grains are lower in protein than flinty ones. Instead of 

 soaking or steeping the grains for several days at 45 C. and subse- 

 quently drying slowly (Brown's method), he suggests that the grain 

 be treated with 40 per cent formalin at the temperature of a boiling 

 water bath for from twenty to thirty minutes. After washing the 

 grains free from formalin and drying them between filters, the charac- 

 ter of the endosperm may be immediately examined. This method is 

 claimed by its author to give a good indication of the value of barley. 

 Beaven d shows that the amount of nitrogen and the quality are closely 

 related, and that high nitrogen barley, accompanied by a steely 

 character of the endosperm, has a higher specific gravity, and that 

 twice as much alcohol-soluble protein is found in such barley as in 

 mealy grains. He also intimates that the nitrogen determination 

 is only useful as an index of quality, other things being equal, and 



Brown, Trans. Guinness Res. Lab., 1903, 1 (1) : 96-127. 



6 Loc. cit. 



c Wochenschr. Bran., 1905, 22: 412. 



d J. Fed. Inst. Brew., 1902, 8: 542. 



