454 ‘WALLACE LARKIN CHANDLER 
It was observed that a 33-per-cent solution of nitrobenzene in olive 
oil would have no apparent effect on dogs if applied externally and if 
the animal was allowed to remain in the open air, in spite of the fact 
that an external application of a solution of this strength invariably 
killed cats and rabbits. Hence a small, short-haired dog" having a 
heavy infection of Demodex folliculorum was bathed thoroly and fre- 
quently with the 33-per-cent solution; but no improvement in the condition 
of the animal could be noticed. 
OBSERVATIONS OF THE ACTION OF NITROBENZENE ON INTERNAL 
PARASITES 
GAPEWORMS 
(Syngamus trachealis) 
Three chicks showing symptoms of gapes were fumigated together 
for two hours at 25-26° C. on June 23, 1917. Two of the chicks developed 
symptoms of nitrobenzene poisoning on June 24. One of these died on 
June 25 and the other on June 26. Two nearly mature pairs of Syngamus 
trachealis were recovered alive from the trachea of the former, and three 
living pairs were taken from the trachea of the latter. The third chick 
developed typical symptoms of nitrobenzene poisoning on June 26. By 
July 8, however, this chick had fully recovered from the effects of the 
drug, and it had also recovered from the gapes by July 8. The recovery 
from the gapeworms, however, cannot be attributed to the action of the 
drug on the worms, since with its improved environment it would in all 
probability have recovered anyway. 
INTESTINAL WORMS 
A number of roundworms (Belascaris marginata) were found in the . 
feces of Dog III on the morning following a fumigation for five hours 
at 18° C. These worms were observed to be dead and their death was 
attributed to the action of the drug. However, roundworms of the same 
species were recovered, very much alive, from the intestines of nearly all 
the dogs examined, even in cases following long periods of fumigation. 
The solution was not tried on long-haired dogs, nor was a stronger solution tried. The animal did 
not lick the solution off, presumably because of the burning taste of nitrobenzene. 
