Solubility of Phosphalic Materials. 
Tlie 100 grains gave 2'27 grains of soluble phospliate of lime. 
A gallon of bone liquid, produced in this way, consequently will 
contain as much as oG o2 grains of bone-phosphate. The inso- 
luble portion of the bone was boiled out a second time with 
10 ounces of water. The resulting clear liquid was found to 
contain '49 of a grain of phosphate, or one gallon would contain 
7"89 grains, showing that with the first reduction of the ammo- 
niacal and nitrogenous compounds the solubility of the phosphate 
of lime became greatly diminished. 
The rotten bone-dust used in this experiment had in 100 parts 
the following composition : — 
Moisture 21-55 
*Organic matter 18-52 
Phosphates of lime and magnesia (bone-earth) .. 39-24 
Carbonate of lime and common salt 19-14 
Sand 1-55 
100-00 
*Containing nitrogen 1'82 
Equal to ammonia 2 '21 
Ordinary bone-dust does not, or ought not to, contain more 
than 1 to 1^ per cent, of alkaline salts ; sometimes, however, 
common salt, or a strong solution of brine, is added with a twofold 
object in view — to increase by a cheap admixture the weight 
of the bone-dust ; and to arrest or prevent fermentation, which 
readily sets up when moist bones, especially those from which 
most of the grease has been boiled out, and which are kept in a 
heap. Fermentation is always accompanied by elevation of tem- 
perature and partial destruction of all organic matter. A heap of 
fermenting, or more correctly speaking putrefying, bone-dust 
heats more or less strongly ; and besides the gases arising from 
the destruction of organic matter, throws off a good deal of water 
in the shape of invisible vapour. The loss in weight sustained 
by keeping ordinary bone-dust in a heap for a period of 3 or 
4 months, according to its condition, generally amounts to 
from 1 2 to 18 per cent. Salt, as is well known, acts as a check 
to fermentation and keeps the heap moist. In the sample of 
rotten bone-dust used in the last-named experiment I found a 
good deal of salt, which appears to have been mixed with it for 
the purpose just referred to. 
It may be suggested that the large amount of phosphates in 
the watery solution of the last sample may have been due to the 
presence of common salt. Direct experiments, however, have 
shown me that the phosphates in bones are not rendered more 
soluble in water by its agency. As the negative results ob- 
