236 Prof. Norton on the Analysis of the. Oat. 
The leaf acts a most important part in the economy of the plant; 
the organic food which is derived from the atmosphere is absorbed 
through the pores of the leaf. In order to perform this function, 
it must spread out a broad expanded surface, which will come in 
contact with as much as possible of the surrounding air. ‘This 
leaf, so extended and yet so thin, requires a degree of stiffness 
that it may stand forth from the stalk, and wave in the breeze, 
rather than hang helplessly down as if withered. For this pur- 
om: a strong framework must be furnished. In Table XVI, the 
rage per-centage of ash from six samples of leaf, is 123, and of 
this fully one half is silica. It is, I think; not unnatural to con- 
clude that this large quantity of ash, so. great a part of which is 
silica, is conveyed to the leaf for the purpose to which I have al- 
luded. When the plant is uncommonly vigorous, and the leaf 
expands to an unusual aaa this framework (see Table XVI) 
may amount to even 20 per cent. 
have now to show that the ash of the leaf varies in quality as 
well as quantity, and for this end give the three following analyses. 
Composition of Ash li hres aaenples of the Oat Leafs. 
opeton Oats = fonts Pile 
l, Light loam. 2. New moss. |Gra i 
Salts soluble in 2 Bee An fe: 
ids, 36°77 56°5 
perepbates of lime, magnesia andi iron, 7°23 3-66 
magnes 10-24 1:33 
Silica, . 2 : : 2 ' 45-75 38-5 
99-99 99-99 
The general composition of the ash from the leaf does not 
greatly differ from that of some samples of top straw. 'T'o the insolu- 
ble silica in the lower line of the above, must be added, in each case, 
or 5 per cent. of soluble silica included in the watery solution. 
Haale found that the top and bottom of the leaf yielded dif- 
ferent quantities, I was desirous of further ascertaining if the 
quality differed also. The following table giv es analyses of the 
ash from the two a 
Taste XX. 
‘ Ash from |. Ash from 
Top of leaf. |Bottom of leaf. 
Salis soluble in east chiefly pe ieee and —- 4326. \7. 4828 - 
Phosphates of lime, magnesia and iron, : 0:85 1:15 
ime and ieggeeaie. ‘ ; es 4 os 3-76 2:78 
ilica, ‘ i = 4 * ey aeeting ae 52:13 47:79 
100-00 00-00 | 
The differences of composition in these two ashes are of the 
same eharacter as those which have been noticed in the straw. 
Though not so striking as those differences, they show that the 
rule as to the preponderance of silica at’the —s _ of solu- 
ble salts at the bottom, holds true in both these parts of the plant. 
(To be continued.) 
