CJ a ten per cent, sululioi. of Atoxyl were then given and the 
disappeaS, only to reappear later and remain more or less constantlj present 
until the death of the animal on the eighty-third day. 
Em««ESTS 8, to and ta.-Only the first of these experiments ^ 
M The treatment was practically identical tn all. The course o 
was much the same and the same disappointing result ensued in each. 
EmKiMENT 8.—See Chart 1. 
Ehbeiuext 10—Trypanosomes appeared in the blood on the fourth day. 
Treatment was commenced on the eleventh day. The 
the blood after a prolonged absence on the thirty-firsl day and ag 
untU the death of the animal at one hundred and seventy-five days. 
I, U in.«.s.i„g to note that a rat .ubinoculated two f 
recunence of the trypanosomes m the early part of e in temoerature 
negative, while another rat inoculated during a very sligM rise 
(ioj°| at a time when no trypanosomes were present in the bloo 
before or after, became infected. 
EmiiuxNT ia.-Parasites appeared in the blood on the ^ 
meot was commenced on the eleventh day. The parasites were P"®«^ ^ 
blood at long intervals until the death of the animal at two 
Subinoculations were made from this animal on the 
fifth, ninety-first, and one hundred and first days. That made on the forty fif^^ 
day was negative, although trypanosomes had been presen ^ , c . 
days previously/those mlde on the twenty-ninlh and one 
were also negative, while that made on the ninety-first ® 
^ve^e not seen in the blood for approximately a month before or after, was 
psilive. The temperature was not elevated at this time. 
Expesiment i8.— Trypanosomes appeared in the of a 
Treatment was commenced on the eighth day by t e mje following day 
twenty per cent, solution of Atoxyl. This dose was repeated oi^ the fcHowing day 
and on the seventeenth and eighteenth days, while one tenth dav The 
P« cent, solution of bichloride of Mercury was " \tS they 
trypanosomes only left the blood for two days ® fthev nersisted arid the 
then reappeared. In spite of the repeated doses of Atoxyl they persisted, an 
animal died on the nineteenth day. 
The early persistence of the parasites, after vigorous ’ 
in this experiment is extraordinary ; they seem to have sudden y 
acquired Atoxyl-resistant characters. Such an occurrence is uniqi 
■"■“iri... - .. .•-"rc^;=.:i.rr;'.= 
T. “i.“ s." 
oae of bichloride of Mercury was given weekly this dose 
trypanosomes appeared in the blood or if the . ^g normal and the 
was repeated at closer intervals, while if the temperature were norm 
parasites absent it was occasionally omitted for one w . it is a typical 
Expewment 25.-This experiment ‘^jiven m full (Ch^^^ experiments, 
example of the course and fatal issue of the disease m ^ 
Experiment 22.— The parasites appeared m t^he course and the 
ment was commenced at once. The tempera u ensued on the seventy-ninth 
patashe.s appeared at irregular intervals, until e 
day 
