Reactions of certain Synt/iesised Proteid-li/se Substances. 341 



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 blood withdrawn from the carotids was hastened by 2 minutes, 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 3f 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 pro- 

 duced 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 pro- 

 nounced 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 Ibs.) ; 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 coagu- 

 lation of blood withdrawn from the animal's carotid was found to be 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-Keymond's Archir,' 1886, p. 397 j 'Proc. Eoj. Soc.,' 

 vol. 40, p. 134, 1886. 



