Manures . 149 
proportions indeed. Thus the ashes of pine, are worthless in our 
families. 
The roots of a plant, do not seem capable of talking up and 
conveying to the sap vessels, any solid substance Hence, ma- 
nures of pabulum can only consist of such substances as being 
composed of hydrogen, oxygen, and carbon, all three, or any two 
of them? are capable of watery solution, and also of being decom- 
posed by the powers of vegetable organization. 
Of these three principles, carbon is the first in importance, as 
forming so large a part of the solid substance of a plant. But the 
solution of carbon in water cannot be effected alone, and it seems 
to have remained as a desideratum in chemical agriculture, till the 
experiments of Arthur Young, Esq. of which I am about to give 
an account. 
In the 43d volume of the Annals of Agriculture, p. 433, there 
is a paper bjr the editor, A. Young, Esq. on the effect of sixty-four 
mixtures of substances intended as manures, on plants of barley. 
The mixtures to be sure are not very scientifically combined, but 
there is no material objection that I see, to the general results of 
the experiments. They were made in 1803. The paper is long, 
I shall therefore extract only the result: premising, that No. 16 
consisted of half an ounce of powdered charcoal, and half an ounce 
of powdered pearl ash, in three quarters of a pint of water, well 
shaken for six hours. 
No. 31 was half an ounce cut straw steeped in putrid stable 
urine for three days. 
No. 64 is nothing but nitre with excess of acid ; being equal 
weights of pearl ash and aqua fortis, in double the weight of wa-* 
ter. 
His notion that the good effect of muriat of soda, common salt, 
is to be attributed to the soda alone, is manifestly owing to imper- 
fect notions of chemistry, and physiology. The paper is closed 
by the following observations, which I present to'the reader. 
u Observations . — That the result may appear in a more simple 
manner, I shall throw the numbers into the order of merit, adding 
together the number of grains and the weight of the straw. 
No. 16 Pearl ash and charcoal fluid - - 715 
31 Straw steeped three days - - 473 
19 Holkham loam - 320 
64 Pearl ash and spirit of nitre - - 296 
60 Soda - - - « 29 1 
