28o 
Trypanosomes were never afterwards seen in any of these rats. One rat died 42 
days after inoculation with trypanosomes. Another, being moribund, was killed 
95 days after inoculation. Trypanosomes were not seen at the autopsy on either 
animal, and a rat sub-inoculated from the rat killed has never shown trypanosomes. 
1 he remaining two rats are still alive, 181 days after inoculation. Rats and mice 
sub-inoculated from them on the 92nd and 156th days have never shown trvpano- 
somes and are still alive. 
Experiment (134). — Six rats received o-Sc.cm. of atoxyl solution in two doses 
on the second and third days after inoculation. The infection was severe; one rat 
died before, two others just after the first dose of atoxyl. Two of the remaining 
rats received no further treatment. One died of trypanosomiasis in 27 days, the 
other in 22 days, after the cessation of treatment. 
In the last rat the course of atoxyl was followed by 1-5c.cn!. of mercury 
perchloride given in two doses on the fifth and eleventh days after inoculation, 
trypanosomes never reappeared. Thirty-one days after inoculation this rat seemed 
ill, it was therefore killed and another rat was sub-inoculated. Trypanosomes 
never appeared, and the sub-inoculated rat died of skin disease three months later. 
Experiment (149).—Five rats each received 05 c.cm. of atoxyl on the third day 
after inoculation. 1 wo rats received no further treatment,- one died (cause of 
death ?) in 16 days after inoculation, the other of trypanosomiasis, in 28 days 
(parasites reappeared three days before death). 
In three rats the atoxyl was followed by 2-7 c.cm. of mercury perchloride given 
m four doses on the sixth, seventh, tenth and eleventh days after inoculation. 
One died (cause of death ?) in 4 o days. The remaining two are still alive, 155 
ays after inoculation. Mice sub-inoculated from them 130 days after inoculation 
have not become infected. 
Experiment (159).—Six rats each received 0*5 c.cm. of atoxyl on the fourth day 
after inoculation. Three rats which received no further treatment showed trypano- 
somes m from 12 to 24 days and died in from 15 to 27 days after inoculation. 
I he other three rats received 2-7 c.cm. of perchloride in four doses on the 
se\ent to tenth clays after inoculation. Trypanosomes reappeared in none of 
them. One rat died on the eighth day after inoculation (cause ?), another on the 
eleventh day (pneumonia). The last rat is alive 133 days after inoculation, and 
mice sub-inoculated from it on the 108th day are not infected. 
Experiment (161).— Two rats each received 0 5 c.cm. of atoxyl on the fifth day 
after moculaUon. One rat had no further treatment and died three days later. 
♦v, 6 er rat rece * vec * 1 ' 9 c - cm - of perchloride in three doses on the eighth, 
en an twelfth days after inoculation. Trypanosomes reappeared on the 15th 
ay. Another 0-5 c.cm. of atoxyl was given at once, but the animal died next day. 
I reatment was probably commenced too late here; both animals 
were almost moribund when the atoxyl was given. It is possible that 
the result might have been better in the mercury-treated rat, had a 
larger dose of atoxyl been given. One dose is probably insufficient 
for so heavily-infected an animal. It may be questioned whether the 
parasites were ever entirely absent from the circulation. 
t . f ' XP ®® I '' EN1 ( 2 ^ 4 )- Six rats w-ere inoculated; one died on the third day. v 
e tourth day the remaining five rats received 1 c.cm. of atoxyl in two dose; 
wo a no urther treatment. Trypanosomes reappeared in them in 20 to 23 day 
er the cessation of treatment, and they died a couple of days later, of trypanc 
somiasis (30 days after inoculation). 
