EDITORIAL OBSERVATIONS. 
93 
ence to their chemical nature and their uses, as well as their 
sources or origin. In like manner, the other questions are 
considered by him, in all of which much familiarity with the 
subject is evinced by him, especially as regards its practical 
application. 
The second division contains “ the chemical changes effected 
in the soil by the growth of the usual agricultural crops.” 
Plants are divided by him into, 
1. Silica plants, as wheat, oats, barley, and rice; in which 
silica forms more than 50 per cent, of their ash. 
2. Lime plants; as peas, beans, clover, lucerne, and the 
potato-herb or top; in the ash of which there is more than 
50 per cent, of lime. 
3. Potash plants ; as turnips, beet-root, and potato tubers ; 
some of which have 70 and others more than 80 per cent, 
of alkaline salts in their ash. 
The following analyses made by chemists of repute, 
showing the per centage of silica, lime, and potash presented 
in the ash, render the distinction clear. 
Salts of 
Potash 
and Soda. 
Salts of 
Lime and 
Magnesia. 
Silica. 
Silica Plants. 
Oat-straw with Corn 
34.00 
4-00 
62-00 
Wheat-straw 
22.00 
7-20 
61-05 
Barley-straw with Com . 
19.00 
25-70 
55-03 
Bye-straw 
18.65 
16-52 
63-89 
Lime Plants. 
Pea-straw 
27-82 
63-74 
7-81 
Bean-straw 
34-00 
54-51 
6-78 
Clover .... 
39-20 
56-00 
4-90 
Potato-herb 
4-20 
59 40 
36-40 
Potash Plants. 
Turnips .... 
81 60 
18-40 
• • • 
Beet-root 
88 00 
1200 
• • « 
Potato-tubers 
85-81 
14-19 
** After looking over these figures, we find that all our common Agri¬ 
cultural plants require nearly the same constituents for their growth, 
differing however, very much, in the relative quantity of each; and, by 
