Commercial Value of Artificial Manures 283 
scale brin<?s no advantage to the consumer, and seldom benefits 
for any length of time tlie producer, who has neither skill, capital, 
nor enterprise to compete with a firm which does a large 
trade. Tlie price which a manufacturer has paid for his raw ma- 
terials, including labour, carriage, bags, &c., is not necessarily 
a criterion of the worth of the manure, because he may have 
bought under serious disadvantages, A man who has not suffi- 
cient chemical knowledge will often select raw materials which 
are very good in appearance, but in reality cannot be employed 
so profitably as others ; or he may not have sufficient capital to 
buy in materials which can only be obtained by taking a ship's 
cargo at a time ; or, if he has capital, he may not have sufficient 
commercial knoAvledge and decision to take advantage of a 
favourable turn in the market. For these and similar reasons 
such a dealer will lose money if he sells the manufactured pro- 
ducts at a rate which will yield a good profit to another vendor 
more favourably circumstanced. 
In commercial analyses and calculations founded upon them, 
the form and condition of the several constituents is too often 
entirely overlooked. This is especially the case with respect to 
the state of combination and mechanical condition in which the 
insoluble phosphates and nitrogen occur. 
Insoluble phosphate of lime may be present in any of the fol- 
lowing forms : ^ or :|:-inch bones, fine bone-dust, boiled bones, 
bone-black, bone-ash, coprolites, apatite, Estramadura phos- 
phate, Sombrero guano, Peruvian guano, and phosphatic guanos. 
Now, in most of these conditions, insoluble phosphate of lime 
has a different agricultural and commercial value. :^-inch bones 
are more effective and cost more than ^inch ; fine dust is still 
more expensive ; and, generally speaking, the finer bone-dust is, 
the more powerful is its action and the greater tlae cost of 
preparation. When bones are acted upon by acid, but not 
applied in sufficient quantity to convert all the phosphate of 
lime which they contain into soluble phosphate, there remains 
in the mixture a certain quantity of insoluble phosphate, which, 
in this condition, is still more valuable than in that of fine 
bone-dust. On the other hand, the insoluble phosphates in 
animal charcoal (bone-black) and even bone-ash are of very little 
use in a turnip-manure. Of still less use to root-crops, if possible, 
are the insoluble phosphates in coprolites, apatite, and other 
mineral phosphate. Intermediate in their action between fossil 
phosphatic materials and bones are, perhaps, certain semi-fos- 
silised guanos, whilst in Peruvian and several phosphatic guanos 
the insoluble phosphates are so extremely minutely divided that 
I am inclined to consider them worth twice as much as phosphates 
in the form of ordinary bone-dust. 
