464 WALLACE LARKIN CHANDLER 
Disturbance of digestive functions 
The retardation, or in some cases even the cessation, of digestive proc- 
esses in the poisoned animals is not wholly understood. Casper (1859) 
observed that in post-mortem examinations of animals poisoned by 
nitrobenzene the stomach contents were always alkaline; and, since the 
acidity of the fluid in the stomach, especially in the pyloric end, has been 
shown to be essential to gastric digestion (Howell, 1918), it is possible 
that nitrobenzene in some way hinders the formation or secretion of 
hydrochloric acid. 
Cerebellar disturbances 
Turning now to the evidence indicating cerebellar involvement, the 
following facts may be noted. From the descriptions it will be seen, as 
already stated, that there is scarcely a single one of the symptoms appear- 
ing in cases of nitrobenzene poisoning that cannot be referred to disturb- 
ances in the cerebellum or the cerebellar paths, barring those which are 
undoubtedly due to a direct action on the blood. Moreover, this con- 
clusion appears to be borne out by histological data, since the 
cerebellum is the only organ in which definite histological changes were 
found. 
Nausea and vomiting— Nausea and vomiting, accompanied by some 
of the symptoms named above, may be due to disorders of the cerebellar 
paths (Jelliffe, 1913). Nausea and vomiting may appear during the 
fumigation process, altho the animal may show no other pronounced 
symptoms for several days; but this does not preclude the possibility that 
nausea and vomiting are the result of the action of nitrobenzene on the 
cerebellum, since it is possible that a sufficient amount of the drug may be 
concentrated in the cerebellum to cause these first symptoms without 
enough being present to produce any further symptoms; moreover, if the 
animal were left in the fumigation chamber for a little longer period, 
the other symptoms would appear very quickly. If the cause of the 
vomiting were to be. ascribed to a peripheral action of the drug, then the 
same explanation would have to be given as for the cause of the vomiting 
after the latent period, it would seem. 
Ataxia.— The type of motor ataxia exhibited by animals poisoned 
by nitrobenzene, especially by dogs and birds, is typically cerebellar. 
