348 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 
Governing Factors in the Choice of Manures. 
In the first place, there are certain factors that govern the choice 
of manures, all of which must be carefully considered. They are 
four in number, viz. : — 
1. The soil. 
2. The crop. 
3. The object for which it is grown. 
4. The season and length of period of its growth. 
The Soil. 
All life and wealth spring from the soil. In it the plant grows, 
in it much of the food material on which the plant depends either 
exists or is placed, and from it the plant takes its nourishment. There- 
fore the soil is the grower's raw material, and by his management 
and manipulation of this raw material he produces the finished article 
—his crop. 
In every other industry the manufacturer pays the most careful 
attention to his raw material ; he knows that his finished article 
depends directly upon it ; he therefore examines it continually, 
watches it carefully, analyses it, and make it his business to know 
exactly its composition, how it will behave under certain conditions, 
and what will be the result of various treatments. 
How many growers make a real study of the soil they are culti- 
vating ? Do they know what it contains, of what it is deficient, 
and how it will respond when this or that manure is applied ? And 
yet it is surely as important to their industry as to any other to have 
an accurate knowledge of the raw material on which they are depen- 
dent for their results. s 
Soils, as every cultivator knows, differ widely. This is easily 
understood if we look at their origin. They are formed mainly by 
the disintegration of the various rocks comprising the earth's surface. 
There are a great number of different rocks and formations in this 
country, as any geological map will show. These rocks have been 
formed and deposited under very varying conditions and at widely 
different periods ; some* under the influence of great heat, others of 
great cold, some were deposited under water, others have been trans- 
ported by glaciers or rivers, some were formed many ages ago and some 
are of comparatively recent origin, so that it stands to reason that 
being formed under these varying conditions they must differ largely 
in composition. 
The first duty, then, of the grower is to ascertain as well as he can 
something of the origin and composition of his soil. 
This of course can best be done by analysis, but care must be taken 
in that case to get the analysis properly interpreted by a capable 
agricultural chemist. Failing an analysis he should certainly have 
