470 
JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 
page 63, may be found a series of analyses of manures then on 
sale for gardeners’ use; and putting aside the cases of actual 
fraud it will be seen that the price paid was generally out of all 
proportion to the value of the material. 
But independently of the question of price there is another 
disadvantage in the use of these mixed manures : the gardener 
is unable to locate for future use the cause of any particular 
effect he may notice as resulting from the application of the 
manure. If, for example, an application of a simple manure 
like sulphate of ammonia produces a certain result, cause and 
effect are definitely connected, and the gardener’s experience is 
richer by a fact for future use ; but if the result has been 
obtained by means of a complex mixture of unknown composi¬ 
tion, the gardener’s knowledge has not been advanced, and he 
has no certainty of being able to reproduce or avoid the case. 
On all grounds—cheapness, security against adulteration, gain of 
experience—it is better for the gardener to buy the simple 
manures and compound them according to his requirements. 
To learn the composition of the simple manures the gardener 
should refer to some book, as, for example, to Mr. Cousins’ little 
book on the “ Chemistry of the Garden,” where also he will 
find an explanation of the proper method of arriving at the 
value of a manure. As to the latter an approximate way of 
arriving at the value of a ton of a given manure is to allow 10s. 
or 11s. for each per cent, of nitrogen, Is. 3 d. or Is. §d. for each 
per cent, of phosphate, or 2s. if the phosphate is soluble, and 
4s. for each per cent, of potash. As an example, a manure con¬ 
taining 6*5 per cent, of nitrogen, 22 per cent, of phosphate, and 
4 per cent, of potash is worth about £6 a ton, made up as follows : 
6’5 at lls.=71s. 6<A, 22 at Is. 6<A=33s., 4 at 4s.=16s., total 
120s. 6<A, to which must be added a certain percentage if the 
manure is bought in small lots. With this preliminary know¬ 
ledge of the nature and price of artificial manures, it remains to 
consider the specific effect of the three constituents, nitrogen, 
phosphoric acid, and potash, which singly, or in combination, 
are the essence of every manure. 
Speaking generally, the nitrogenous manures promote growth 
and the vegetative development of the plant, leaf, and shoot, 
rather than flowers and fruit. For example, a fruit tree over¬ 
dressed with nitrogen will run to wood, the leafage will be 
