Solubility of Phosphatic Materials. 
183 
forms In which bone manure is sold, is affected by their relative 
solubility in w<ater. 
The raw materials employed in the first series of bone experi- 
ments were : — 
1. Very hard shank-bones of ox, coarsely ground. 
2. Ordinary commercial bone-dust made from rather hard 
bones. 
3. Ordinary commercial bone-dust made from rather porous 
bones. 
4. The pith of ox-horns (sloughs), a very porous description 
of bone. 
5. Boiled bones (the refuse bones of glue-makers). 
An excess of each of these substances was placed with pure 
distilled water, in glass bottles, in some instances for three days, 
in others for a week or 12 days ; the liquid was shaken at 
intervals repeatedly, then allowed to settle and filtered clear. 
The clear liquid was then evaporated to dryness, the residue 
heated in a platinum capsule, and taken up with a few drops of 
hydrochloric acid. The solution was then precipitated with 
ammonia, and the precipitate collected, washed, dried, and 
weighed, when the following results were obtained 
Amount of Bone-pliosphates dissolved hy one gallon (70,000 grains') of 
Distilled Water from different kinds of Bone-dust and Boiled Bones. 
Bone-phosphates 
dissolved by a 
Gallon of Water. 
1 XT J v 1 1, r i 1st Experiment after 3 days . . "48 e,rains 
1. Hard shank-bones from oxen ioj io .qa 
1 2nd „ 12 „ -80 „ 
2. Commercial bone-dust (made) 1st Experiment after 1 week 3'68 „ 
from rather solid bones) . . J 2nd 
3. Commercial bone-dust (made) 
from rather porous bones) . . J 
4. Pith of ox-horns 
5. Boiled bones (ghie-makers') 
refuse) | 
In explanation of these results, I would observe that the mate- 
rial employed in the first experiment was specially selected, 
washed perfectly clean, and broken up into coarse bits, which, 
before the experiment was begun, were long soaked in cold water 
in order to free them from any soluble impurities always present 
in ordinary bone-dust. 
The very hard bone-dust, it will be seen, was scarcely at all 
affected by water in the course of three days ; after a longer 
period it was somewhat more dissolved ; but even then very little 
phosphate of lime passed into solution, for the actual quantity of 
bone-phosphates amounted to only eight-tenths of a grain per 
gallon, whilst in seven days abovit four times as much was dis- 
)> 
4-24 
)) 
>I 
5-40 
)) 
5-36 
>> 
)>. 
5-90 
!) 
