EXPERIMENTS ON THE COMPOSITION OF WHEAT GKAIN. 377 
I r 
would have been 35'6 grs. instead of 34"2 — a very trifling difference, 
due not to a difference in the size of the two sorts of seed, but to a 
slight difference in density in favour of the translucent grains. This 
difference in density is brought out very plainly when the seed is placed 
in a strong solution of chloride of calcium under the air-pump. With 
a solution of specific gravity 1'247, 71 per cent, of the grains sink, 29 
per cent, float. In 100 of the heavy grains thus separated there are 
generally 35 to 38 translucent grains, and only 18 opaque; while in 
100 of the light grains thus separated, there are usually only 10 trans- 
lucent grains, and as many as 70 opaque grains. With these observa- 
mi 
of seed^ I may introduce my experiments on their chemical diflerences. 
The amount of water in the selected seeds was practically the 
same : 
Percentage of Water. 
Spalding-red. Hallett's white, 
Translucent 16-12 ..... 14*34 
Opaque 16-10 14'47 
But the percentages of nitrogen were remarkably different : 
Percentage of Nitrogen, 
Spalding-red. Hallett's white. 
Tranalucent ...... 1-792 2-088 
Opaque 1-405 1521 
It is usually assumed that the percentage of " flesh-formers " or 
albuminoids in feeding-materials may be deduced from the percentage 
of nitrogen, by multiplying it by 6 "2 5. According to this calculation, 
we find the percentage of albuminoids in the translucent grains of 
Hallett's white wheat to be 13*06, while in the opaque grains it is 
only 9'51. In Spalding red wheat, the flesh-formers in the translucent 
grains amount to 11-20 per cent., and to 8'78 per cent, only in the 
opaque grains. Assuming the medium grains to be intermediate in 
composition, it is easy to calculate what amount of nitrogen the whole 
wheat would contain. The calculated and experimental percentages of 
nitrogen are 
Spalding-red. Hallett's white. 
Percentages of nitrogen calculated , 1*598 .... 1"745 
found . . 1-600 .... 1-752 
» >» 
The chief conclusions at which I have arrived from my experiments 
r 
2 
