494 WALLACE LARKIN CHANDLER 
Filehne (1878) undertook experiments for the purpose of clearing up 
some of the questions concerning which the findings of other writers 
varied in their essential details. Those questions were: What is the 
reason for the latent period? Is nitrobenzene converted into hydrocyanic 
acid in the body? Is it converted into anilin in the body? What is the 
action of nitrobenzene on respiration and on the blood? Filehne also 
includes among his list of problems the following: spectroscopic analysis 
of the blood of animais poisoned experimentally by nitrobenzene; the 
action of nitrobenzene on blood outside of the animal; the action of 
nitrobenzene on the nervous system and on muscle tissue; and the thera- 
peutic principles to be employed in treating cases of nitrobenzene 
poisoning. 
Filehne maintains that the explanation of the latent period on the 
basis of time required for the absorption of the drug is not sufficient, 
since it cannot explain the extremely rapid course of the drug in some cases. 
Furthermore, Filehne found nitrobenzene in the blood within twenty-five 
minutes after it had been injected subcutaneously; he states also that 
animals heavily poisoned very quickly exhale nitrobenzene in sufficient 
amounts to perfume large volumes of water. He further claims that 
the latent period does not depend on an accumulative action of the drug, 
since a single drop introduced directly into the blood stream of a rabbit 
will kill the animal instantly. He thinks that the rapidity of the action 
depends on the rate in which the nitrobenzene passes from the blood 
to the central nervous system. In cases exhibiting rapid action the transfer 
takes place quickly and convulsions result (in dogs), while if the transfer 
takes place slowly the action is retarded and paralysis is the principal 
symptom. In the frog, Filehne observed only paralysis. He was able to 
produce rigor mortis also in the hind leg of a frog immediately after 
injecting nitrobenzene into the aorta, even in cases when the muscles 
had been severed from their connection with the central nervous system 
by cutting the ischiadic piexus, thus showing that nitrobenzene does 
exert a direct action on the muscle tissue. Filehne argues that the reason 
why Ollivier and Bergeron faiied to show any action of the drug on the 
exposed frog leg was that the lymph in which the muscles are bathed may 
have served to exclude the drug from direct contact with the muscles. He 
writes that he himself has observed similar results when the muscles were 
thus protected. 
