912 THE PRINCIPLES OF BOTANY. 
Composition of 100 parts. 
Air- dried 
Barley. 
Air-dried 
Oats. 
Substances containing nitrogen, and capable of 
forming flesh 
13 parts 
13'6 
Substances not containing nitrogen, and fitted 
for support of animal heat and formation of fat 
69* „ 
70*3 
Ashes 
3*3 
Water 
14 „ 
12-8 
Total 
100 „ 
100*0 
These results are very conclusive, and they tend to show 
us that however slow we may be to understand the reason for 
a general custom, there is generally a sound one at the bottom 
of long established usage. Hence, then, the botany of cereals 
does not explain all the facts without the aid of the chemist ; 
at the same time it is a moot question whether here even 
chemistry is complete without a knowledge of botany, or that 
botany in the full elucidation of its principles includes 
chemistry. As touching inquiries of this nature, most 
instructive matter may be gathered from a consideration of 
the ash of barley taken in connection with its growth and 
habits. 
The following is given by Professor Yoelcker as the means 
of several analyses both of grain and straw, and both are of 
interest in several particulars. To the farmer, as showing the 
matter taken off the soil in a crop of barley ; to the vegetable 
physiologist, as explaining how this crop is so much better on 
some soils than on others. Prom these analyses the farmer 
Comparative Analysis of Barley. 
Grain. 
Straw. 
Potash 
Soda 
Lime* 
Magnesia 
Oxide of iron and loss 
Phosphoric acid 
Sulphuric acid 
Silica 
Chloride of sodium 
Grains. 
15-61 
5-03 
3-06 
8-01 
1-24 
35-68 
1-22 
28-97 
0-45 
Grains. 
22-17 
0-84 
7- 59 
3- 55 
4- 35 
3-22 
2*61 
46-30 
9-37 
Total 
99-30 
100-00 
