Analyses of Ashes of Plants. 
671 
It will be seen from this table that whilst the first two specimens 
give an equal amount of ash on the whole grain, the ash of the 
Hour yielded by them is very difl'erent. Tlie ash on the whole 
grain is not affected to any considerable extent by the soil, whilst 
that of the flour is evidently connected with it. The flour of the 
specimens grown upon clay agree very nearly with each other in 
the quantity of ash, as do also the two grown upon sand — t)io two 
former being however very distinct in this respect from the two 
latter. In estimating the gluten in the flour, we were obliged by 
circumstances to adopt the mechanical method, which is by no 
means so satisfactory as that of ascertaining the amount of nitro- 
gen. The gluten was dried by an oil-bath, but in all probability 
its determination in specimen 41 is in error from imperfect drying. 
The per centage of ash in the gluten of all four specimens is so 
similar as to warrant us in believing that the quantity of gluten 
itself would have been smaller in the last but from the cause just 
mentioned.* Of the ash of the gluten, 94 per cent, is insoluble 
matter, which must consist entirely or in great part of phosphates 
of lime and niasfnesia. 
Ag-ain, it will be seen that whilst in the whole grain the phos- 
phoric acid does not appear in any way to correspond with the 
per centage of ash in the flour, the outline, at least, of such a 
connection is observable. A small amount of ash in the flour 
being accompanied by a small per centage of phosphoric acid on 
the whole grain, this would indicate that the phosphoric acid is 
contained in largest quantity not iu the bran, but in the flour. 
We have probably here said enough to show that there is great 
hope that by following up the clue here attbrded — by the separate 
analysis of the bran, floui-, starch, and gluten of several specimens, 
we shall be enabled to trace the connection existing between the 
mineral and vegetable composition of plants, and to discover the 
office performed by the different inorganic compounds in the ash. 
It is extremely probable, as before said, that the elementary prin- 
ciples — the starch and. the gluten — may have a constant and 
invariable asli, both as to quantity and quality, and that the whole 
diflerences observed in the ash of the entire grain are to be attri- 
buted to alterations in the proportions of the different vegetable 
principles which it contains. The point once established, the ne- 
cessary mineral composition of different plants will become a 
matter of most simple comprehension, being readily determined 
by a knowledge of its vegetable composition. Possessed of this 
information, there would be no necessity for the analysis of any 
but extreme specimens, the produce of particular culture ; but it 
The gUiten was separated from 500 grains of flour, and the whole of 
it burned for the per centage of ash. 
