Hemin Crystals. 



23 



strength of reagents constant. This method appears to yield larger 

 crystals than those obtained by the old method. 



12 (268) 



The influence of ether anesthesia on the excretion of 

 nitrogen by dogs. 



By PHILIP B. HAWK. 



[From the Laboratory of Physiological Chemistry of the Department 

 of Medicine of the University of Pennsylvania.] 



A series of nine experiments were made upon four dogs, the 

 experiments ranging in length from 7 to 1 7 days. The plan fol- 

 lowed was to get the animals into a condition of nitrogen equi- 

 librium, then to induce ether anesthesia continuously for periods 

 varying from y 2 hour to 4^ hours. The initial influence of the 

 ether was to cause an increased excretion of nitrogen, the average 

 daily percentage increase varying from 6.5 per cent, after 30 

 minutes anesthesia to 43.5 per cent, after 3 hours narcosis. In 

 the latter case the animal had been anesthetized on each of the two 

 preceding days and therefore this large increase may represent the 

 cumulative effect of the anesthesia. In six of the nine experi- 

 ments the average daily excretion of nitrogen continued above 

 normal during the entire experimental time after anesthesia was 

 induced, the ultimate average daily increase varying from 3.5 per 

 cent, for a 5-day period following 2 hours anesthesia to 17.5 per 

 cent, for a 14-day period after ether narcosis had been induced for 

 periods of 1, 2 and 3 hours on 3 successive days. In the three 

 experiments which showed a diminished excretion of nitrogen after 

 anesthesia the normal output of nitrogen was decreased 1.5 per 

 cent., 1.8 per cent., and 4.0 per cent, as the result of anesthesia 

 periods of y 2 hour, 4^ hours and 1 hour respectively. 



In each experiment the anesthetic had a diuretic effect, the 

 extent of the diuresis varying from an initial average daily increase 

 of 5.7 per cent, in the volume of urine after y 2 hour of anesthesia 

 to an increase of 24.8 per cent, after an anesthesia period of 4^ 

 hours. The diuretic effect continued until the close of the experi- 

 ment in every instance except one, the average daily percentage 



