52 DR DAVY ON THE COAGULATION OF THE BLOOD. 
moistened with dilute muriatic acid, was for a short time kept over the vessel, 
crystals of muriate of ammonia formed on it, that is, after evaporation, and as 
viewed under the microscope. The clot was of about equal consistence through- 
out, and tolerably firm; cut into pieces, each piece, tested by the approach of the 
rod dipped in muriatic acid, showed, by the fumes produced, the presence of 
ammonia. The serum, which in a few hours had separated from the crassamen- 
tum, had an ammoniacal odour. 
Experiment 3.—To a mixture of water and aqua ammonice, formed of 12 
grains of the former and 1 grain of the latter, in a vial of one half-ounce capacity, 
277 grains of blood were added as it flowed from the divided vessels; the glass 
stopper was instantly introduced, and, to secure admixture, the bottle was in- 
verted two or three times. In about two minutes and a-half, coagulation had 
taken place. 
Experiment 4.—277 grains of blood from the same fowl were caught in a 
larger and thicker bottle, exceeding that used in the preceding experiment by 856 
grains (more than double its weight), and exercising therefore a greater cooling 
influence. This blood coagulated in about three minutes. 
Experiment 5.—A small portion of blood from the same fowl fell on a flag- 
stone in the open air, the temperature of which, ascertained by the thermometer, 
was 40°. Ten minutes after the last had coagulated, this retained its fluidity, 
and after other ten minutes, it was only feebly coagulated. 
Experiment 6.—To a mixture of 13 grains of water, and 14 grains of aqua 
ammonie of specific gravity 88, in the half-ounce vial, the blood of a fowl as it 
issued from the divided vessels was added to overflowing; the stopper was imme- 
diately introduced. The blood which overflowed, it is remarkable, became tena- 
cious and viscid in less than a minute, even before another portion caught in a 
separate vessel had coagulated ; the latter undergoing the change in about two 
minutes. The stopper taken out after an hour, the contained blood was found 
coagulated ; the coagulum was soft and easily penetrated, very tenacious 
and viscid, of a dark colour, and pungently ammoniacal. In twenty-four 
hours it had become somewhat firmer, and in three days a little more so, 
showing a slight degree of contraction; but no serum had separated from the 
clot. A minute portion of it detached, which was not easily effected, owing to the 
tenacity of the crassamentum, exhibited, under the microscope, a confused appear- 
ance; diluted with serum, and stirred, no blood corpuscles were detached, and 
using a compressor to spread out the little mass, the whole had the aspect of a fine 
granular tissue. This blood after twenty days experienced little change; and the 
remark applies equally to the two portions,—that contained in the stoppered vial, 
and that which overflowed, received into a wine glass and merely loosely covered 
with tin-foil; both emitted an odour of the volatile alkali, slightly tainted as if 
from incipient putrefaction ; the colour of each had become of a rusty brownish 
