o7G Chemical Composition and Commercial Value of 
constitution of pure bones is well known, and affords a ready 
means for checking such errors. It has appeared to me more 
desirable to prove this assertion by the results of direct investiga- 
tions of my own than to base it upon calculations derived from 
published analyses of bones. 
With this view I prepcared samples of ox and horse bones, 
sfdecting the cleanest and hardest. The bones, after being care- 
fully scraped, were broken into small pieces, Avhich were soaked 
in cold distilled water for a week, in order to remove any 
soluble salts. After that time they were reduced to powder ; 
this was repeatedly washed with distilled water. The bones thus 
purified were next burned in a platinum capsule at a moderate 
heat, the ash was again washed repeatedly with distilled water, 
then moistened with carbonate of ammonia in order to convert 
any caustic lime which might have been produced during burn- 
ing into carbonate. Direct experiments, however, showed that 
the heat employed was not sufficiently strong to drive off 
carbonic acid. 
Although both the bones and their ash were washed with a 
great deal of water, it was found impossible completely to remove 
the alkalies. Even the hardest bones contain some potash and 
soda. By long washing, the amount of alkalies may be dimi- 
nished, but hitherto I have not been able to obtain a bone-ash 
perfectly free from alkalies, though I have washed small quantities 
for longer than a fortnight on a filter. 
Prepared in this way, the ash of horse and ox Ijones, in a 
perfectly dry state, was found to consist of: — 
Composition of the Ash of — 
Horse-bones. Ox-bones. 
♦Phosphoric acid 40-29 39-81 
Lime 55-01 55-43 
Magnesia -84 -80 
Potash -25 -49 
Soda -03 -60 
Carbonic acid 2-99 3-52 
Sulpliuric acid traces -04 
Chlorine traces -06 
99-41 100-75 
* Correspoiiding totribasicphosphatel g-.gg 86-''5 
of lime (bone-earth) .. ../ 
The ash of the ox-bones was not washed quite so long with 
water as that of the horse-bones, and contains for this reason 
rather more potash and soda. These results are here stated as 
they have been actually obtained in the analysis. In bone-ash, 
