94 
CONCRETION FROM A HORSE'S STOMACH. 
solution gave a strong alkaline reaction. The magnesia 
jhus obtained was collected upon a filter, washed with 
boiling water, incinerated and weighed; it yielded 14.45 
per cent. 
Another portion of the powdered concretion, dried over 
sulphuric acid in vacuo at ordinary temperature, yielded 
hygrometric moisture 1 per cent ; incinerated, it yielded 
volatile matter (water and ammonia ) 51.70 per cent. 
In order to determine the amount of ammonia, another 
portion of the powder was introduced into a small tubulat- 
ed retort with carbonate of soda and water. The neck of 
the retort was adapted to a small tubulated receiver, con- 
taining dilute hydrochloric acid, and having adapted to its 
tubulure a nitrogen bulb, such as is used in ultimate organic 
analysis ; this also contained dilute hydrochloric acid. The 
mixture in the retort was then evaporated to dryness, and 
at the close of the operation, air was drawn through the 
apparatus to insure the absorption of the last portion of 
ammonia. 
The ammonia thus obtained was estimated by precipita- 
tion by chloride of platinum as in organic analysis, and 
yielded 0.71 per cent. 
Hence the composition of the concretion is as follows : — 
Phosphoric acid, - - 32.40 per cent. 
Magnesia, - - - - 14.45 " 
Water, ----- 50.35 < ; 
Ammonia, - - - - .71 " 
Insol. inorganic matter, .45 " 
" organic " .64 u 
Hygroscopic moisture. 1.00 (i 
100.00 
It will be seen from this, that the amount of ammonia is 
too small to be considered an essential ingredient of the 
concretion. Assuming it to exist in the state of double 
phosphate of ammonia and magnesia with water (NH 4 0, 
