76 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 9 



young males increased slightly in weight with practically no difference. 

 The young gained regularly in both sets and no difference was shown 

 between the young fed by a normal animal and the 3^oung fed by a 

 fumigated animal. The female guinea pigs were perfectly normal. 

 There was no abortion, although nitrobenzene has been used to produce 

 abortion. These animals have now been fumigated for nine continuous 

 weeks and the two sets are indistinguishable. One large male was 

 fumigated for ten weeks and was then killed and his tissues examined. 

 So far as could be noticed, macroscopically, there was no injury, but 

 microscopically a very shght congestion was noticed in some of the 

 shdes of the lung, but not sufficient to affect the animal. It was 

 noticed that chickens w^hich had been fumigated retained the odor of 

 nitrobenzene in their bodies for several clays after fumigation. Fumi- 

 gated chickens lose this odor in five to seven days after fumigation. 

 A short-horn cow was obtained and fumigated over night. The milk 

 was tested by a number of people, some of whom noticed no difference 

 between the milk of the fumigated animal and normal milk while 

 others detected a very slight trace which,, however, they agreed would 

 -have passed unnoticed under normal conditions. Milk will take up 

 nitrobenzene if the cow is milked in the same room in which the cow 

 had been fumigated. The milking 24 hours after fumigation showed 

 no trace of nitrobenzene. 



Some animals seemed to be more susceptible to nitrobenzene than 

 others. An exposure of ten to twelve hours in a saturated atmosphere 

 of nitrobenzene would produce the death of a cat while guinea pigs, 

 sheep, etc., are not injured by a similar dose. It is,, however, a well 

 known fact that cats are particularly susceptible to coal tar derivatives. 

 This does not detract from the value of nitrobenzene in destroying 

 fleas on cats, as they easily stand a fumigation of one and a half hours. 

 The nitrobenzene is taken into the lungs and hence to the blood from 

 which it is probably removed by means of the kidneys. Herbivorous 

 animals which urinate frequently seem to be less affected. The author 

 and another person remained in a small room while it was fumigated 

 with nitrobenzene for one and a half hours, destroying the house flies 

 in the room. A slight irritation to the eyes and throat and a sweetish 

 taste at the back of the mouth were the only symptoms noticed and no 

 after-effects were discovered. 



The Influence of Temperature 



Professor Derby^ of the University of Minnesota, Department of 



Physical Chemistry, worked out the amount of nitrobenzene which 



would saturate an atmosphere at different temperatures. From the 



curve, it is seen that at 83° F. about one drop is contained in a cubic 



