156 Society for Experimental Biology and Medicine. 



the same symptoms but in a gradual way ; the animal dies after five 

 or six hours. A dose of between 3 and 4 grams causes no serious 

 effects, but for six or eight hours after its administration the animal 

 remains in a soporous state ; it sits in one place with eyes closed 

 and head drooping ; a loud noise wakes it up and it attempts to 

 move about or to eat, but in a few minutes it falls asleep again. 



This toxicity of the magnesium nitrate is apparently due to its 

 greater absorption from the gastro-intestinal canal. It is certainly 

 not due to its diminished elimination through the kidneys ; on the 

 contrary it acts in some degree as a diuretic, and, when given by 

 subcutaneous injection, the animal withstands a somewhat greater 

 proportionate dose of the nitrate than of the sulphate or chloride, 

 probably because the nitrate increases somewhat the diuresis. As 

 to the share which the anion, the nitrate end of the compound, 

 may have in the toxic effect, I do not wish to make a positive 

 statement ; but I doubt whether it is of any importance. I studied 

 the toxic effects of sodium nitrate administered by mouth and com- 

 pared the manifestations with those seen after administration of 

 magnesium nitrate ; the contrast was sharp. Even with a dose of 

 1 2 grams of the sodium nitrate per kilo there is never such an 

 anesthesia or paralysis as that caused by the magnesium salts ; on 

 the contrary the animal is all excitement and restlessness. Besides, 

 the late death of the animal after administration of sodium nitrate 

 is due to circulatory disturbances, whereas after poisoning with 

 magnesium salts, the animal dies of respiratory paralysis. 



109 (252) 



On the promoting influence of heated tumor emulsions on 



tumor growth. 



By SIMON FLEXNER and J. W. JOBLING. 



\From the Rockefeller Institute for Medical Research.] 

 We have on several occasions presented to this Society some of 

 the results of the study of a transplantable sarcoma of the rat, and 

 we wish to-day to record an effect on the growth of the tumor 

 which is produced by inoculation of the rats with an emulsion of 

 the tumor cells, previously heated for half an hour to 56 0 C. This 



