38 
The remainder of the serum was dried at about 37° C. An amount 
of this dried serum, representing 3 c. c. of the original serum, was 
redissolved and injected into each of two guinea pigs, which were 
then tested forty-eight hours later for their susceptibility and found 
sensitive. 
The remainder of the dried serum was divided into two lots. 
One part was heated to 130° C. for ten minutes, the other to 
100° C. for ten minutes.- These two lots were then redissolved and 
injected into four guinea pigs, each animal receiving an amount of 
the dried heated serum equivalent to 3 c. c. of the fluid serum. All 
four guinea pigs were tested forty-eight hours later for their sus- 
ceptibility. Those that received the serum heated to 130° C. for 
ten minutes did not show any reaction following the second injec- 
tion, whereas those receiving the dried serum heated to 100° C. for 
ten minutes responded to the intoxicating injection. 
As this serum was heated and redissolved without being pulver- 
ized some difficulty was experienced in getting it into solution, and 
the negative results at the higher temperature may be due in part 
to this fact. It is extremely interesting, however, to find that an 
antibody resists so high a temperature as 100° C. 
SENSITIZING ACTION OF DRIED HORSE SERUM. 
As a control upon the sensitizing action of heated dried serum, 
five guinea pigs were sensitized with varying amounts of dried 
tetanus antitoxin from 1/25,000 gm. to 1/800 gm. and subsequently 
tested by the injection of 6 c. c. of normal horse serum, intraperi- 
toneally. All the animals were shown to be exceedingly sensitive. 
Table Xo. 17. — Sensitizing action of dried serum. 
G. P. No. 
G. P. 
weight. 
First injection. 
Inter- 
val in 
days. 
Second injection. 
Result. 
311 
1/25000 gm. dried tetanus 
antitoxin, subcutane- 
ously. 
79 
6 c. c. normal horse (Frank) 
serum , intraperitoneally. 
Dead in 40 min- 
utes. 
312 
1/5000 gm. dried tetanus 
antitoxin, subcutane- 
ously. 
79 
J 
6 c. c. normal horse (Frank) 
serum, intraperitoneally. 
Dead in 22 min- 
utes. 
313 
1/2500 gm. dried tetanus 
antitoxin, subcutane- 
ously. 
6 c. c. normal horse (Frank) 
serum, intraperitoneally. 
Dead in 20 min- 
utes. 
314 
1/1200 gm. dried tetanus 
antitoxin, subcutane- 
ously. 
79 
6 c. c. normal horse (Frank) 
serum, intraperitoneall y . 
Very severe symp- 
toms. 
315 
1/800 gm. dried tetanus 
antitoxin, subcutane- 
ously. 
I 
6 c. c. normal horse (Frank) 
serum, intraperitoneally . 
Dead in 40 min- 
utes. 
