and was carried from the ward to the animal room in a light-proof, sterile bag. 
The blanket was left in the cage with the monkeys over night. Observations were 
recorded upon the monkeys daily for a period of 16 days, during which time no 
eruption and no temperature reaction appeared. The animal was variolated on 
the skin on the seventeenth day of the experiment with virus No. 260. A typical 
primary lesion developed at the site of inoculation. 
One of the remaining animals of this series died on the fifteenth day of the 
experiment, before the immunity had been tested by skin inoculation. At autopsy 
there was no evidence of variola in this animal. The 3 other monkeys were shown 
to be susceptible to variolation by skin inoculation. 
Summary.—Five monkeys showed no clinical symptoms of variola 
after exposure to a smallpox-infected blanket. Four of these animals 
were subsequently shown to be susceptible to variola by skin inoculation. 
The fifth animal died before its immunity was tested, but no anatomical 
evidence was found that it had contracted variola. 
(f) Attempts to inoculate the monkey by exposure to a smallpox 
patient.—This experiment was undertaken as a further test of the reac- 
tion of the monkey to conditions which would bring about an infection 
with smallpox in man. 
No. 240. Adult male, WM. cynomologus. This monkey and 4 others were placed 
in a cage which was kept in a room for 16 hours with a smallpox patient in the 
vesicular stage of the disease. The animals were kept under observation for 
16 days. No eruption and no temperature reaction was observed. On the seven- 
teenth day of the experiment the animal was inoculated on the abdomen with 
variola virus No. 260. A typical primary lesion developed at the site of 
inoculation. 
Of the 4 remaining monkeys of this series 2 reacted positively to subsequent 
variolation on the skin while 2 gave no reaction. 
Summary.—Five monkeys exposed to a, smallpox patient did not de- 
velop symptoms of variola. Three of these animals were subsequently 
shown to be susceptible to variolation by skin inoculation. 
(g) Attempt to inoculate by exposure of the orang-utan to smallpox 
fomites.—This experiment was planned to determine if an animal higher 
in the scale than the monkey would contract smallpox under conditions 
in which man becomes infected. 
No. 197. A young female orang-utan was given a blanket which had just been 
taken from a case of smallpox in the vesicular stage of the disease. The animal 
at once wrapped herself in the blanket and used it until the following day, 
when a clean blanket was substituted for the infected one. During the following 
eighteen days the animal was kept under constant observation. No exanthem 
appeared and the variations in the body temperature which occurred were ex- 
plained by intercurrent infection. The animal was subsequently variolated on 
the skin and yielded a positive reaction. 
Summary.—An orang-utan exposed to smallpox fomites did not de- 
velop symptoms of variola. The animal was shown subsequently to be 
susceptible to variola inoculata by skin inoculation. 
