152 
Analijscs of the Ashes of Plants. 
Mean composition of the Ash of Peas and Beans, and of their Straws 
(including the Pods). 
Peas. 
Beans. 
F'ea-Straw. 
Silici 
1 
24 
0 
88 
5 
36 
Phosphoric Acid . • 
34 
81 
31 
87 
4 
50 
Sulphuric Aciil . . 
5 
68 
4 
50 
5 
66 
Carbonic Acid 
1 
n 
1 
94 
14 
74 
6 
32 
8 
fiS 
37 
99 
Magnesia .... 
6 
57 
6 
55 
6 
73 
Peroxide of Iron . 
0 
59 
0 
36 
1 
76 
40 
19 
42 
13 
17 
17 
0 
65 
0 
90 
2 
48 
Chloride of Sodium . 
0 
68 
1 
90 
3 
57 
Chloride of Potassium 
1 
42 
0 
34 
Total . . . 
99 
97 
100 
00 
99 
96 
Hcan- 
^'tiaw. 
3-86 
7-35 
3- 21 
22-73 
21 -29 
4- 88 
O-'JO 
21 -26 
4-56 
9-05 
0-90 
99-89 
The averages in the foregoing- table are, it will be remembered, 
those of 6 analyses of peas and 6 of beans, and 4 analyses of pea- 
straw, and the same number of bean-straw. I'he mineral com- 
position of peas and of beans is, then, remarkably similar : their 
respective straw-ashes do not so closely resemble each other, 
but are still of the same character. 
On the methods of Preparirig and Analysing the Ashes of Plants. 
In the preceding Report in this Journal we have alluded to the 
questions which have been raised concerning the accuracy of the 
ordinary methods of burning plants for ash analysis. 
The substances which it would be possible, according to known 
chemical phenomena, to dissipate in the combustion of the plant 
are — carbonic acid, sulphuric acid, phosphoric acid, and chlorine, 
and the metallic bases of the alkalies potash and soda. The other 
constituents of plant-ashes — namely, silica, oxide of iron, lime, and • 
magnesia — cannot, it is conceived, be liable to loss in any form. 
\st. Of Carbonic Acid. 
Rose, to whose paper on this subject we have before referred, 
has pointed out discrepancies in regard to this constituent which 
are found to occur in the analyses of plants by different chemists, 
and, by reference to the alleged composition of the blood, has 
shown how very necessary it is that some belter method should 
be adopted in order to obtain coincident results. It must be 
remembered that, although carbonic acid is not an actual con- 
stituent of a vegetable or animal substance, but is produced in the 
combustion, a knowledge of the quantity in different ashes is 
of importance in the discussion of many physiological questions. 
