458 WatLacre LARKIN CHANDLER 
a test tube with a few drops of nitrobenzene. When examined spectro- 
scopically, the sample showed no trace of the band, but only oxyhemo- 
globin. The sample was allowed to stand overnight, but the band even 
then failed to appear. Another sample was taken, diluted as before, and 
shaken with nitrobenzene. It was then placed in an incubator at a 
temperature of from 37° to 38° C. The methemoglobin band, above 
described, made its appearance at the end of four hours. However, 
since no control sample was incubated at the same time, this test is not 
a positive proof that nitrobenzene can form methemoglobin in blood 
outside of the animal. 
The results described above agree fairly well with the findings of 
Filehne and others. There has been some disagreement regarding the 
nature of the band in question; however, a sample of methemoglobin 
prepared in the laboratory showed an absorption band in exactly the 
same position as that occupied by the “ nitrobenzol band.” 
HISTOLOGICAL EXAMINATION OF THE TISSUES.OF ANIMALS POISONED BY 
NITROBENZENE 
DOGS 
Four half-grown dogs, all from-the same litter, were kept as nearly 
as possible under the same conditions. On January 24, 1917, three of 
them (Dogs E, F, and G) were placed together in the fumigation chamber 
and fumigated for a period of five and one-half hours at a temperature 
of 20° C. They were removed from the tank at 10 p. m., apparently 
unharmed. 
On January 25 Dog F showed a shght lameness, hid himself away 
in a dark box, and did not eat well. The other two animals were apparently 
normal. 
On January 26 all three of the dogs were found to have developed 
pronounced symptoms of nitrobenzene poisoning. The symptoms were 
of the same general character in each, but were more advanced in Dog F. 
All the animals were able to crawl about; they had a partial use of the 
fore legs but were not able to use the muscles of the hind legs. The 
knee-jerk reflex was good in ‘each of the animals. There appeared an 
incoordination of the muscles of the neck, but there were no signs of 
