Reactions of certain Synthesized Proteid-like Substances. 343 



It gives negative results with the reactions of Liebermann and 

 Adamkiewicz, but gives the typical red coloration when .the solid 

 plates are heated with an alcoholic solution of alloxan (Krasser's 

 reaction). It is separated from solution by neutral salts in a 

 manner similar to the colloid a and Grimaux's colloids. The scum 

 also redissolves in distilled water giving an opalescent straw- 

 coloured solution. It is precipitated by silver nitrate, lead acetate, 

 and mercuric chloride, as well as by phosphotungstic, phospho- 

 molybdic, and trichloracetic acids, and by acetic acid and potassium 

 ferrocyanide. 



In the entire absence of salts it is not coagulated on boiling, but, 

 on the addition of a trace of a soluble salt of either sodium, magne- 

 sium, barium, strontium, or calcium, a coagulum is obtained on 

 heating to 74 C. 



The fractional heat coagulation of this substance will be dealt with 

 in a subsequent section. 



The effect produced by the intravascular injection of various 

 quantities of this body is illustrated by the following expeiiment: 



Experiment 8. Brown mongrel (weight 27 Ibs. 7 oz.) ; anaesthe- 

 tised with ether and morphia. The jugular vein on the one side, 

 and the carotid artery on the other, were exposed, and cannula3 

 inserted into them. The colloid y3 was injected into the jugular vein, 

 and samples of blood withdrawn from the artery. The following 

 table shows the rate of clotting of the various samples : 



(1) Before injection of the colloid, the blood clotted in 10 minutes 



30 seconds. 



(2) 5 c.c. of 075 per cent, solution of colloid dissolved in 075 per 



cent, saline injected. A firm clot formed in 17 minutes 

 8 seconds. 



(3) 10 c.c. more injected. Loose clot in 22 minutes. 



(4) 10 c.c. more injected. Firm clot in 31 minutes. 



(5) 10 c.c. more injected. Firm clot in 13 minutes. 



(6) After interval of 5 minutes a second sample of carotid blood 



formed a firm clot in 7 minutes 30 seconds. 



(7) 7 c.c. more injected. Firm clot in 7 minutes 30 seconds. 



(8) 10 c.c. more injected. Firm clot in 6 minutes. 



(9) 15 c.c. more injected. Firm clot in 3 minutes. 

 (10) 10 c.c. more injected and proved fatal. 



Immediate post-mortem examination revealed loose clots in vena 

 cava inferior, and jugular vein, and pronounced clots in portal vein, 

 and right ventricle. 



This experiment shows the " negative phase " after injection of small 

 quantities of the colloid ft, and the typical hastening of the coagulabilit ,j 

 of the blood withdrawn from the carotid after the intravenous injection of 



VOI.K. 20 



