Solubility of Phosphatic Materials, 
187 
bones ; this explains why much less phosphate was found in 
the second than in the first solution. 
Experiments with Bone-Meal and Ivory -Dust and Boiled Bones 
{irfuse hones of ylue-mahers). 
Ivory-dust and bone-shavings, being the turnings or raspings 
of hard bones, contain rather less organic matter and more phos- 
phate of lime than common bone-dust. The sample employed 
in the experiments was thus composed : — 
MoisUiro 13-12 
♦Organic matter 26'12 
Phosphates of lime and magnesia (bone-earth) . . 53'74 
Carbonate of lime 5'39 
Alkaline salts '78 
Sand -85 
100-00 
♦Containing nitrogen 3*28 
Equal to ammonia 3*98 
Ivory-dust, when free from sand, chalk, or other adulterating 
matters, is a valuable refuse, which may be applied to all 
purposes for which bones are used in agriculture. It is particu- 
larly useful to the farmer for drying wet and very acid mineral 
superphosphates. Coprolite superphosphate when rich in 
soluble phosphate is very apt to get pasty in its transit from the 
manure-works to the farmer, and in such a condition it is not 
easily or advantageously applied to a root crop. Moreover, very 
acid mineral superphosphates should not be applied as a turnip 
manure without admixture with some other material, on light sandy 
soils deficient, as is often the case, in lime or other basic mineral 
constituents which abound in clays or marly soils, and which, 
by neutralising or precipitating the acid phosphate and free sul- 
phuric acid sometimes present in very acid superphosphates, pre- 
vent injury being done to the young plants. 
Ivory-dust is not only an excellent material for drying up and 
greatly improving the quality of mineral superphosphates ; it is 
likewise a very handy material for the production of home-made 
bone superphosphate ; its dusty condition at once secures the 
absorption of oil of vitriol, and a dry superphosphate can be 
obtained from it without loss of time and without difficulty by 
being mixed in a wooden tub* with 25 to 30 per cent, of brown 
sulphuric acid diluted with an equal weight of water. Such 
a mixture almost directly dries up sufficiently to admit of being 
placed in a heap ; indeed it is only necessary to mix the acid and 
ivory-dust as rapidly as possible together. 
* A small tub or barrel cut in two may be employed for the purpose, and a 
considerable quantity may be made in a short space of time. 
