136 



Scientific Proceedings (92). 



189 (1367) 



The toxic action of nitrobenzene, with special reference to the 



cerebellum. 



By M. Dresbach and W. L. Chandler. 



[From the Department of Physiology and Biochemistry, Cornell 

 Medical College, Ithaca, N. Y.] 



The toxic action of nitrobenzene has been comparatively little 

 studied in an experimental way. The investigations here re- 

 ported have been in progress about two years. Dogs, cats, 

 rabbits, guinea pigs, white rats and mice, hens, pigeons, frogs, and 

 certain insects and blood parasites have been used. The animals 

 have in all cases been exposed to air saturated with the vapor of 

 the nitrobenzene at various temperatures in a special metal box 

 of forty cubic feet capacity, and so arranged that good ventilation 

 was insured. The periods of exposure varied from one to twenty- 

 four hours, or even longer, as in case of rabbits and guinea pigs; 

 with other animals the exposure was usually much shorter. The 

 effects obtained vary with the type of animal somewhat. In dogs 

 and birds the nervous system disturbances predominate, with 

 lighter dosage, while in the other mammals used blood changes are 

 more prominent, especially in severe poisoning. The details of 

 these variations will be published later. At this time we give only 

 the central nervous system reactions. These are of a type that 

 are associated with cerebellar disturbance especially. Thus, 

 in dogs an early asthenic condition in the limb and neck muscles, 

 staggering gait, typical cerebellar nystagmus, unequal pupils, 

 "circus" movements may be seen. In birds a body attitude and 

 rotating motion of the head are strikingly similar to those in birds 

 with cerebellar lesions. The animals may recover, sustain per- 

 manent disturbance of muscular coordination, or die. Symptoms 

 develop at any time up to three or four days after exposure to the 

 vapor. 



Histological study of various parts of the brain and cord re- 

 vealed remarkable chromatolytic changes, apparently confined 

 to the Purkinje cells of the cerebellum, in all animals showing 



