PHYSIOLOGICAL ACTION OF NITROBENZENE V,APOR ON ANIMALS 469 
absorption of the nitrobenzene from the blood, and its retention by the 
liquid fats of the body in which it is easily soluble. As the concentration 
of the poison in the blood lipoids and fats diminishes, in ‘relation to its 
concentration in the body fats, the nitrobenzene is given up again to the 
blood; and in the course of time, a sufficient concentration of the poison 
in the lipoids of the cerebellar or other brain cells is reached to produce 
an onset of the motor symptoms. The time required to bring this about 
(the latent period) depends on the same factors as those on which the size 
of the lethal dose depends, and is undoubtedly hastened by the ingestion 
of solvents of nitrobenzene, such as alcohols, fats, oils, milk, and the like. 
Possibly, also, the condition of the brain lipoids at a given time may be 
an important factor in hastening or retarding the absorption of nitroben- 
zene by these lipoids. 
6. Nitrobenzene cannot be used, with any degree of safety, for the 
fumigation of animals to destroy their external parasites. The lethal 
dose for birds and mammals is rather variable but it may be very small; 
and from these experiments it will be seen that apparently a shorter period 
of fumigation at a given temperature is required in order to kill a domestic 
animal than to kill even a fair proportion of either fleas or biting lice. 
However, as has been pointed out by the writer in a previous paper 
(Chandler, 1917), the drug may be used, with the exercise of caution, for 
collecting external parasites from animals, by fumigating the animals at 
low temperatures and for short periods of time — at a temperature not 
over 20° C., and for a period not longer than one and one-half hours. 
Under these conditions the parasites may. be stupefied without any appre- 
ciable damage being done to the host; but the drug is dangerous to handle 
under any conditions. 
7. Because of the extreme toxic properties and the subtle action of 
nitrobenzene, the following uses of this drug should be prohibited by 
legislation: for perfuming soaps, lotions, and pomades; as a solvent in shoe 
polish, floor wax, and the like; and especially as an ingredient of flavoring 
extracts, confections, and liqueurs. The drug should be regarded as one 
of the most dangerous of poisons, and its sale and use should be regulated 
by law just as in the case of any other deadly poison. 
8. Nitrobenzene should be given serious consideration as an industrial 
poison. Munition plants, dye works, and other factories which handle 
