36 ' REPORT—1845. 
Equally striking differences are observed in the other parts. In the top straw were 
38°56 per cent. of salts soluble in water; in the middle straw 53°56; in the bottom 
straw 77°46. As the soluble salts increase from the top downwards, so the silica in- 
creases from the bottom upwards. The per-centage of soluble and insoluble silica in 
the bottom straw is 17-28 ; in the middle 40°48; in the top 48°44. The leaf is in its 
composition not very unlike the top straw. In the chaff, phosphoric acid again ap- 
pears in the watery solution, seldom present in that solution from the ash of the straw 
or leaf, and the per-centage of soluble silica is very great. 
3. The quality of ash varies in the same parts in different samples. This even- 
extends to the same variety of oats. I compare two samples of Hopeton oats, one 
grown in Northumberland and the other in Fife. There are differences in every part, 
but I will illustrate my point by the straw. In the top, middle and bottom straw, 
respectively, of the Northumberland sample, the proportions of salts soluble in water 
are 41:96, 53°22, 77°46; while in the same divisions of that from Fife they are 71-70, 
84:03, 90:26. There is a corresponding difference in the silica, increasing upwards 
as before. The same excess of soluble salts prevails through the whole of this 
sample. 
These examples illustrate the proposed points, and show the necessity of further 
investigation. This is all that I proposed to do in the present incomplete state of my 
researches. 
On the Ashes of Narcotic Plants. By F. C. Wricutson. 
The great problem of chemistry of the present day in its application to agriculture 
is, to determine the conditions necessary for a soil to produce the largest amount of 
any given crop of animal food—of food for man or beast. The solution to this ques- 
tion will in some measure be found when we have ascertained the proportions of 
mineral constituents required by plants of culture for attaining full perfection. The 
analysis of these plants alone, however, is not sufficient; we must have analyses of 
the weeds growing upon soils, of plants unfit for the sustenance of animals; for it is 
shown that they rob the farmer, not only of a large amount of mineral manure, but 
also of considerable quantities of that valuable ingredient, ammonia; and we shall 
not have obtained the data necessary for an improved and rational system of culture 
until we include in our ash-analyses a considerable number of weeds and useless 
plants, especially those of the most destructive kind. Some of them are well known 
to the farmer to be of serious injury to his erops mechanically ; with respect to their 
abstracting important constituents of the soil, their injurious effects cannot be ques- 
tioned. ‘These plants contain more than 8 per cent. chlorine, and from 30 to 50 per 
cent. alkalies in their ashes. The dried leaves contained between 6 and 8 per cent. 
of nitrogen. 
On the Ashes of Wheat. By Wit1am Suarp, F.R.S. 
Mr. Sharp noticed that the amount of the ashes of wheat was given by Professor 
Johnston from Sprengel as 1-177 per cent., whereas Sprengel himself (p. 446. vol. ii. 
of his ‘ Chemie ftir Landwirthe ’) states it to be 1:777; Dr. Daubeny, on the other 
hand, gives Sprengel’s analysis as 2137, both of which alterations are made on the 
supposition of a misprint in Sprengel’s book. This led Mr. Sharp to undertake some 
experiments in order to ascertain the truth; and about a hundred experiments were 
performed, with great care, on varieties of red and white wheat, grown on different 
soils and climates in England, Germany, Sweden, Poland, Holland and Saxony. The 
results gave answers to the following questions :—I1st. What is the average amount 
of inorganic matter in the grain of wheat? This varies within the limits of 1°5 and 
1:75 per cent. 2nd. Does the quantity of inorganic matter bear any relative propor- 
tion to the specific gravity of the grain, that is, to its weight per bushel? ‘The ex- 
periments show that a steady inverse ratio is maintained between the proportionate 
weight per bushel and the amount of ashes. Wheat weighing 64 lbs. per bushel yields 
1*5 per cent. ; aud this amount gradually increases till wheat weighing 58 lbs. per 
bushel gives 1°75 per cent. of incombustible matter. 3rd. How much inorganic matter 
is removed from the soil of an acre of land by the grain of a crop of wheat? The 
answer to this practical question is one pound per bushel, From these experiments the 
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