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finely divided virus was tried by Zulzer. The subcutaneous injection of 
blood from a case of hemorrhagic variola was done by Roger and Weil. 
The data on the constitutional reaction of the inoculated animal are 
rather scanty. Fever has been noted by Zulzer, by Copeman, by Béclére, 
Chambon, and Menard, and by Magrath and Brinckerhoff. Diarrhoea 
was observed by Copeman and by Béclére, Chambon, and Menard. Three 
investigators report animals dying after inoculation of the skin with 
variola virus. In the case of Béclére’s animals it seems evident that 
there was intercurrent disease. The animals inoculated with fatal results 
by Roger and Weil and by Magrath and Brinckerhoff were shown to have 
died either from streptococcus septicemia or from tuberculosis. 
In all experiments where the skin was inoculated, a pock which closely 
simulated that produced by vaccination was observed to develop at the 
site of inoculation. 
A general exanthem was observed by Zulzer, Copeman, De Haan, and 
by Magrath and Brinckerhoff. The virus seemed to have lost this power 
of producing an exanthem when transferred from one monkey to another 
(De Haan). 
The immunity developed by inoculation with variola virus has been 
studied by Copeman and by Roger and Weil. The former found that 
variolation of the monkey protected against subsequent inoculation with 
vaccine or variola virus. The latter found that inoculation of the skin 
with variola virus did not confer complete immunity to later inoculation 
with vaccine, although the animals were immune to variolation by skin 
inoculation. 
That the serum of a variolated monkey had “anti-virulent” properties 
when put in contact with vaccine was shown by Béclére, Chambon, and 
Menard. 
It was shown by De Haan that a strain of variola virus which had been 
passed from one monkey to another for six or seven generations was 
inoculable on the calf. 
A careful analysis of the evidence in the literature seems to show that 
the disease produced in monkeys by various inoculations with variola 
virus has always been one which conforms closely to the type of variola 
inoculata as seen in the human subject. This was emphasized by Ma- 
grath and Brinckerhoff. 
We find no reference to the occurrence of smallpox on monkeys in the 
wild state among the species inhabiting the Old World. The statement 
is sometimes made that monkeys in the Western Hemisphere suffer from 
epidemics of the disease in localities where smallpox is epidemic among 
men. This statement seems to be based upon the following data. 
Andrew Anderson, in his book on Fevers, gives an excerpt from a 
letter that he received from a friend who was traveling in Central Amer- 
ica. This statement has frequently been referred to and it seems worth 
while here to give it in full. 
