Jan. 8,1917 
Immunity Studies on Anthrax Serum 
41 
Ascoli (1) separated the pseudoglobulin from anthrax serum and 
showed that the immune bodies were contained in this fraction. Appar¬ 
ently the technic of serum fractioning was not sufficiently developed at 
that time to enable Ascoli to concentrate the pseudoglobulin into a small 
volume as well as to separate it from the serum. 
In his very extensive monograph on anthrax, Sobemheim (10) makes 
no mention of the fractionation of the immune serum, probably because 
the serum itself was satisfactory for most purposes (p. 696). 
ANIMAL-INOCULATION TESTS 
The protective power of the globulin concentrates was determined by 
inoculation experiments, mostly on guinea pigs, of which 263 were used. 
The preliminary experiments soon showed that the immune bodies were 
present in the globulin preparations. It is highly probable that the loss 
of immune bodies during the concentration was not very great ; but an 
exact statement is not possible because at the present time there is 
neither a unit of anthrax toxin nor of immune body known. They have 
not yet been studied sufficiently to be standardized. The general state¬ 
ment may be made that the globulin concentrates are more potent than 
an equal volume of the corresponding serum. Only those details of the 
tests which are of special interest are mentioned. One of the main objects 
of the tests was to obtain data that might throw light on the problem 
of the nature of the immune bodies—whether they were different from 
or identical with the pseudoglobulin. The tests made so far are not 
easy to interpret, and little light is thrown by them on the problem. 
In test 5, Table II, it was desired to ascertain whether a given weight 
of pseudoglobulin had the same protective power when present alone 
as in the globulin preparations, and when present with all the other 
serum constituents as in the serum administered. 
In the first animal-inoculation tests the virus employed was a 24- 
hour bouillon culture of an attenuated strain of Bacillus anihracis , pre¬ 
pared by inoculating from an agar culture the amount of anthrax bacilli 
that can be taken up on a standard loop into a tube containing 10 c. c. 
of bouillon; 0.25 c. c. of such a culture constituted the dose. Eater, 
however, a standardized suspension of anthrax spores in normal salt 
solution (4,000,000 spores per cubic centimeter) was employed, the dose 
also being 0.25 c. c. The injection of the serum and globulin prepara¬ 
tions was made intraperitoneally, followed in 48 hours by a subcuta¬ 
neous injection of the virus. Virus “Davis-C” represents a culture of 
B. anihracis uniformly fatal for guinea pigs and rabbits; “Davis-D” is 
fatal for guinea pigs but not rabbits; and “Chestertown” is fatal for 
sheep, cattle, and horses. 
From the results obtained (Table II) on 3 lots of 12 guinea pigs, 
which had been injected with varying amounts of serum 48 and globulin 
48, it would seem that a given weight of globulin had approximately 
