578 



Dr. A. D. Waller. New Method for the [June 17, 



T 10 

 T 8 

 T6 

 T 4 

 T 2 

 T 0 



500 



e 



g 400 

 3 300 



S 200 



a 



■~ 100 



a; 

 o 

 a 



hours 



Fig. 2.— Laurel leaf weighing 2 3 grammes, 

 in weak picrate + CHCI3 4/1000; fluid 

 decanted every ten minutes and com- 

 pared with a colour scale. Incubator 

 at 40°. 



T 12 





HOO 



T 10 



Line. 



500 



T 8 



1 



u 



tut 



400 



T 6 



llionths 



300 



T 4 



s 



g 



200 



T 2 



HON 



100 



T 0 







days 12 3 4 



Fig. 3. — Laurel leaf weighing 2 grammes, 

 in 50 c.c. weak picrate + CHCl, 

 4/1000 ; fluid changed each day and 

 compared with a colour scale. 



Quantitative Estimation of Hydrocyanic Acid in the Blood and Tissues of 

 Animals, and of Man, after Death hy Hydrocyanic Acid Poisoning. 



Estimations were made by distilling the blood or minced tissue, mixed with 

 water acidified by tartaric acid, into a solution of sodium picrate. They 

 have been made with the blood and other tissues of animals that had 

 received, by intravenous injection or by injection into the stomach, 

 amounts of hydrocyanic acid, or of potassium or sodium cyanide, much 

 above and rather below the reputed minimum lethal dose; also with the 

 blood and tissues of animals that had died by inhalation of HON, in whose 

 blood therefore the actual amounts of HCN inhaled had been automatically 

 limited by the arrest of respiration. As will be seen from the following 

 summary of experiments, tlie method lends itself to the quantitative determina- 

 tion ^os^ mortem of very minute amounts of hydrocyanic acid. It is applicable 

 up to (if not beyond) 48 hours post mortem (Experiment 17). And, as 

 shown in the tabular digest giving milliohths ingested per gramme of 

 body weight and millionths found per gramme of tissue, it brings into 

 evidence that the organs in which HON is found to be most abundant 

 (and for which, presumably, its affinity is relatively great) are the heart 

 and the brain. As shown in Experiment 3, it passes in the blood itself 

 from the plasma to the corpuscles. 



The method is simple and expeditious. Each distillation requires about 

 half-an-hour, and, as shown by fig. l,an hour's digestion at 40° is sufficient to 

 bring out the full (98 to 99 per cent.) depth of tint in the distillate. 



Experiment 1. — Cat ; weight, 2 kilos. ; chloroform anresthesia. Death by injection into 

 the femoral vein of 10 c.c. of a 1 per cent, solution of HCN. Blood removed from the 

 heart immediately after death and defibrinated. 



