34 
HORTICULTURE AS A SCIENCE. 
of knowledge, we should only embarrass and discourage by an attempt to elucidate 
the direct processes of analysis : and, therefore, propose to adopt a more simple 
order of investigation, by which we hope to remove many difficulties, and to instruct 
any one to acquire some degree of certainty and precision in estimating the structure 
(if the term be admitted) of an earth, and its applicability to the operations of hor- 
ticulture. 
At an early period after the formation of the English Agricultural Society, now 
" The Royal Society of Agriculture" a prize essay on soils was written by the Rev. 
Mr. Rham, which was printed in No. I. of the Society's Journal. This gentleman 
perceiving the difficulties attendant upon a regular analysis, by chemical agents, 
devised and propounded a mechanical process, which possesses high merit, and has 
our cordial approval. It has already been honourably noticed in more than one 
periodical of wide circulation ; but, able as it is, we find the processes too elaborate 
for ordinary practice ; and after all, the reverend gentleman has been constrained to 
introduce one or more chemical agents into his routine. 
The three chief earths, which will be found in almost every good garden, are 
loam, heath or moor-earth, (erroneously called peat,) and leaf-mould. Sand of every 
kind is in constant requisition, but by it we understand the silver, or Calais white 
sand, which needs no investigation, being, when pure, little else than flint in a state 
of minute division, and therefore unsusceptible of decomposition. 
Loam is the staple of the land ; it occurs abundantly, but varies extremely in 
its texture and quality. That species which is propitious to every operation of the 
garden and floriculture is soft and velvety, fat or unctuous, but so little liable to 
adhere or clod, that if a handful of it be compressed tightly, when just so moist 
as to be in a fit condition for the use of potting, and be sufi*ered to fall from the hand, 
it will break on the ground, and separate into fine particles. Such a loam will 
remain firm, yet open, in a garden pot, without cracking into fissures or detaching 
itself from the sides. It is composed of pure clay, very fine sand, iron in a con- 
dition resembling ochre, and generally a small proportion of chalk. In naming 
pure clay (alumina), we do not mean clay in the common sense of the word, because 
the stiffest and most binding clays of the field contain a very large portion of sand. 
But to prove the existence of the above-named earths, it is necessary to have recourse 
to chemistry ; and as it is not our present object so to do, we must restrict our investi- 
gation to texture only ; therefore, whenever it is intended to compare two kinds of 
loam, the gardener should possess himself of a sort which he knows to be good, 
approaching in quality to that we have above described, and by submitting it to the 
following simple operations two or three successive times, in order to prevent error 
in early practice, a standard will be obtained by which to judge of the value and 
applicability of any loam that is found elsewhere. The instruments of analysis 
might consist of a pair of scales, sufficiently accurate to discover a single grain, 
a set of troy weights, three or four jugs or tall narrow glasses with lips, a tin 
drainer with fine holes, a small hair-sieve, another of gauze, a glass or earthenware 
