225 
INVESTIGATION OF SOILS. 
' As the period of torpor and repose is now established, and plants, with few 
exceptions, should be in a state of rest, it will not be irrelevant to the objects of 
floriculture to devote a few pages to the consideration of those discoveries which give 
promise of great improvement in that art. In our late notice of Guano, some idea 
was conveyed of the extreme caution required to avoid danger from the application 
of an agent so comprehensive and powerful. We are thus led further to insist 
upon the necessity which exists of becoming experimentally acquainted with all the 
media that gardeners employ in their several operations of culture: for to the 
present hour, as in agriculture, so in the floral departments, men act upon mere 
empirical routine, ignorant of principles, of the causes producing effects, and of 
ithe mode of correcting errors of misapplication. 
As a qualifier of what we assert, it must be avowed that plants, like animals, 
are liable to disease, — they are subjects of mortality, and, at the best, can only 
vegetate on, and progress to the close of their existence. We see an unhealthy 
I subject, and wonder at the cause ; recourse is had to change of soil and modifica- 
tion of treatment ; but without effect ; it is weak — it cannot be nourished — 
languishes, and dies. Thus disease may prevail without the fault of the gardener ; 
and so it will ever be. But this unhealthy condition is not at all connected with the 
[ inquiry which claims present attention. 
I A very few years have elapsed since it became apparent that to understand the 
proper treatment of any vegetable, the substances which enter into its organic 
structure ought to be discovered ; and some progress has already been made in this 
important branch of physiology. 
Pending the course of experiments which will, at least, detect those inorganic 
elements that withstand the action of fire, and therefore are traceable to the soil in 
which the plant grows, we must be content to ascertain the constituents of the soil 
itself, and this we can effect with a degree of accuracy that could scarcely have been 
anticipated, by the ablest chemist, even at the period when Sir Humphrey Davy 
detailed his process of analysis before the Board of Agriculture. 
If by tracing, and assuring himself of this fact the gardener acquire something 
like a correct knowledge of the earths he employs, and which experience has shown 
to produce the highest condition, he gains a great deal, and thereby converts mere 
conjecture into certainty. 
Every gardener and florist of large practice is quite aware that, besides the 
multifarious varieties of loam, there are the earths called mow/J, which have their origin 
in vegetable matter ; and also a considerable number of soils, vaguely styled peat^ 
all adapted to the habits of the hair-rooted plants, but differing materially 
in quality and texture. Now, by the processes of analytic chemistry, the compo- 
VOL. XII. — NO. CXLII. 
G G 
