54 DR DAVY ON THE COAGULATION OF THE BLOOD. 
ments I have to make mention of are of two kinds: one set have for their object 
to ascertain what is the amount of loss of ammonia from evaporation or volatiliza- 
tion, supposing it to exist in the blood, and it has an opportunity to escape in the 
act of coagulation; the other set were designed to ascertain the solvent power 
of ammonia acting on coagulable lymph,—that substance, the passing of which, 
from the liquid to the solid state, gives rise to the phenomenon under considera- 
tion. 
Experiment 9,—In the same half-ounce vial as was used in the experiments 
already described,—the aperture of which was one-thirtieth of an inch in diameter, 
—13'7 grains of aqua ammonice were introduced, carefully weighed, confined by 
aglass stopper. The stopper was withdrawn ; it was replaced after eight minutes, 
and again weighed; there was no appreciable loss; the thermometer in room 
52°. Added 13°95 grains more of the solution of ammonia; after balf-an-hour 
the loss sustained was ‘05 grain. There was next added a portion of white of 
egg, equal in weight to 171:26 grains; after forty-six minutes the loss was -03 
grain. The same immersed in water of 98° for five minutes suffered a loss of 
‘O01 grain.* 
In these experiments the specific gravity of the aqua ammoniz had not been 
ascertained ; it was certainly higher than ‘88, having been kept some months, and 
the bottle holding it repeatedly opened. In the following trials, aqua ammoniz 
of the specific gravity named was used. 
Experiment 10.—The same vial containing the blood mentioned in experiment 
number 6, holding 14 grains of aqua ammonie, was carefully weighed ; the stopper 
was withdrawn, replaced after ten minutes, and again weighed, the loss experienced 
was ‘Ol grain. The case of the balance, in which the vial was left open during 
the ten minutes, had a strong smell of ammonia. 
Experiment 11.—To 2147 grains of water in the same vial, 16-9 grains of 
aqua ammonize-were added ; in eight minutes after withdrawing the stopper, the 
loss sustained was ‘01 grain. The body of the vial was now immersed in 
water at 95°, and kept there for ten minutes; the loss suffered was equal to -04 
grain. 
Do not the results of these experiments go far to prove that, even on the sup- 
position of ammonia existing in the blood in a volatile form, no appreciable quan- 
* Plunged into water of 210°, the white of egg coagulated, though a large proportion of the 
ammonia still remained in the solution. A mixture of white of egg and bicarbonate of potash simi- 
larly treated, an effervescence occurred, and a coagulation formed. This I notice to show that the 
presence of an alkali does not prevent the coagulation of albumen by heat, leading to the inference 
that its liquid state is not owing to the little alkali which it contains, I may mention another fact 
having the same bearing. A portion of milk, to which a little ammonia had been added, was put by 
to see how long it would keep sweet, air being excluded, the bottle being filled and well secured with 
a glass stopper. It was long forgotten; after two or three years it attracted attention. Now, it was 
found that a film of black matter, which proved to be sulphuret of iron, was formed, covering the 
whole of the inside of the vial ; that the milk had acquired a brown hue, the cream on its surface 
remaining almost colourless, and that though it was alkaline, yet a small portion of curd had formed 
