Analyses of Ashes of Plants. 
655 
(1841-42) was remarkable for extreme drought. In these opposite 
conditions the weight of straw to grain was — 
In 1840-41 as 100 to 40. 
In 1841-42 as 100 to 90. 
Converting tliese numbers into others which may be compared 
with our own, we have — 
Grain. Straw. 
In 1840-41 .... 1000 to 4160-2 
In 1841-42 .... 1000 to 1116-0 
The latter number very nearly approaches our own mean for 
this year (1250) ; the other instance exhibits a most extraordinary 
deviation. 
Boussingault states the ordinary relation of straw to grain at 
Bechelbron to be as 100 to 38 (or as 2631, grain being taken at 
1000), and quotes in support of this being a probable average the 
following results of other continental observers : — 
For 100 of straw— Or Grain as 1000, 
Thaer . . gives . . 50 of grain . . . 2000 straw. 
Podewils . „ . . 35 „ . . . 2857 „ 
Berger . . „ . . 41 „ ... 2292 „ 
Block . . „ . . 33 „ ... 3030 „ 
Dierexen . „ . . .39 „ . . . 2564 „ 
Schwertz 44 „ . . . 2272 „ 
It is not stated whether the chaff is included in the calculation, 
but we suppose that it is. In the back numbers of the Journal of 
this Society will be found many accounts of the estimation of straw 
and grain of wheat, in which the proportion of straw and chaff to 
grain is generally found to be between 1^ and 2^ that of the 
grain. 
If, then, our results merit confidence, they would plainly prove 
either that the straw of this year is exceedingly small in quantity, 
or if (as we believe) its quantity does not fall far short of average 
years, that the proportion of straw to grain is usually very much 
overstated. It will presently be seen in what respect this conclusion 
is important in respect to the mineral matters of the wheat plant. 
The quantity of chaff in wheat does not, as far as we can discover, 
depend upon the amount of straw, but bears a general though 
perceptible relation to the grain. To the latter it stands in the 
proportion of 1 to 5^ on an average of 1 cwt. of chaff to every 10 
bushels of wheat. 
Both straw and chaff are found in some cases to present singular 
deviations from the usually observed proportions : this is peculiarly 
the case in Piper's thickset wheat. Spec. 32, where the straw does 
not much exceed the half of the weight of the grain — the chaff, 
however, remaining constant. 
We do not observe that the soil has exercised much influence on 
the quantities of straw and chaff — the average of clays, of sandy 
and calcareous soils, being in our experiments very similar. 
Of the specific gravity of the grain we have before spoken ; but 
