57 
ANALYSIS OF SOILS. 
We resume this subject at the point where we closed our previous remarks, 
No. p. 10. In considering humus as the basis of vegetable nutriment, we 
follow the bent of other writers, who, however lucid their theories may be to their 
own minds, fail to bring conviction to the understanding of others. Humus is 
a newly-appropriated Latin word, which strictly means nothing more than the 
earth or ground — mould' therefore the term is improper — a falsification; for, 
strain the sense hard as one may, it is impossible that humus^ humi^ — the ground, 
— can be made to apply to that black, perfectly reduced substance, of an old dung- 
mixen, or mass of fermented vegetable matter which is used as manure. 
Our philosophers describe humus (which, they say, is "produced by the slow 
decay of animal and vegetable matter") as "a dark, unctuous, friable substance, 
nearly uniform in its appearance, — a compound of oxygen, hydrogen, carbon, and 
nitrogen, — found in the greatest abundance in rich garden mould, or old neglected 
dunghills, — a product of organic power, such as cannot be compounded chemically. 
" It is the product of living matter, and the source of it. It affords food to 
organization : without it nothing material can have life. In the state in which 
it is usually found in the earth, it is not soluble in water, and we might have some 
difficulty to comprehend how it enters into the minute vessels of the roots of 
plants ; but here the admirable provision of Nature may be observed. Humus is 
insoluble and antiseptic ; it resists further decomposition in itself and in other 
substances in contact with it. It remains for a long time in the earth unimpaired ; 
but no sooner is it brought into contact with the atmosphere by the process of 
cultivation, than an action begins. Part of its carbon uniting with the oxygen of 
the atmosphere, produces carbonic acid, which the green parts of plants readily 
absorb ; while its hydrogen with the same forms water." " The residue forms 
a soluble extract^ and in that state is taken up readily by the fibres of the roots." 
Here then we have a concise view of the " humine " theory, a compendium of 
all that has been written concerning humus or humic acid, — in plain terms, of the 
existing philosophy of manures obtained by the analytic experiments of the 
laboratory. We will sift this theory a little ; for, while perceiving a great deal 
of inductive truth in it, we cannot fail to detect some hypothetic fallacies. 
We deny the correctness of the term humus in the abstract ; for black spit-dung 
is not earth ; yet w^e will, for the sake of conciseness, leave it without further 
comment, provided it be clearly understood that the substance so called possesses 
nothing in common with the earths proper, to which it is only applied by art as 
an adjunct, or into which it enters by the natural processes of vegetable decay. 
It is readily admitted that native loams, and soils in general, contain fibrous or 
VOL. VII. NO. LXXV. I 
