the injection of the colloid was also hastened; thus after 20 c.c. of the colloid had been injected, the time of complete coagulation of blood withdrawn from the carotids was hastened by 2 minutes, after 30 c.c. by 3 | minutes, and after 35 c.c. by 4 minutes.
It will be evident that the results recorded above are similar to, if not indistinguishable from, those produced by the intravenous injection of a nucleoproteid.
When slowly introduced into the circulation of dogs, and to a much lesser degree of rabbits, in minute quantities, the effect produced on the coagulability of the blood is the converse of that resulting from the introduction of larger quantities. This effect is more pronounced than that obtained by the intravenous injection of Grimaux’s colloids, and more resembles Wooldridge’s* “ negative phase,” which is characteristic of a nucleoproteid, but is not so pionounced as the result obtained with that substance.
This result is illustrated by the following experiment:—
Experiment 5.—Large black mongrel. Anaesthetic, ether and morphia (weight, 60 lbs.) ; 1 c.c. of a 0'025 per cent, solution colloid a was injected very slowly, the injection being distributed over half an hour, at the end of which time the retardation of the time of coagulation of blood withdrawn from the animal’s carotid was found to be 8 minutes 30 seconds. A second dose of 1 c.c. of the same solution injected and distributed over 20 minutes caused a further retardation in the time of coagulation of the carotid blood of 2 minutes; but a third injection distributed over a similar period of time hastened the coagulability of the blood that had been previously retarded, so that the retardation, as compared with the time of coagulation before the injection of the colloid, was only 1 minute 30 seconds. After a still further injection of the colloid, the blood coagulated more rapidly than in the normal condition, and finally, when the dose was pushed, intravascular coagulation of the animal’s blood occurred, and death resulted.
If the colloid is separated from the solution by saturation with magnesium sulphate, sodium chloride, or ammonium sulphate, as before described, and the scum redissolved in distilled water, the opalescent solution obtained will, when intravenously injected into pigmented rabbits, produce typical intravascular coagulation. Repetition of the process of precipitation and redissolving however, destroys the physiological activity in a manner similar to the result produced with both nucleo-proteids and Grimaux’s synthesised colloids.
If the solution formed by the passage of a stream of sulphuretted hydrogen over the precipitate formed by the addition of lead acetate to the colloid is injected intravenously into pigmented rabbits or
- Wooldridge, ‘ Du Bois-Reymond’s Archiv,’ 1886, p. 397; ‘ Proc. Boy. Soc.,’
vol. 40, p. 134, 1886.
