21 
Effect of 0.1 gram CaCl^ for fifteen consecutive days before the second injection of horse 
serum, 104 days after the sensitizing injection — Continued. 
Xo. 
G. P. 
First injection. 
Interval. 
Second injection. 
Result. 
5554 
j 
1 
0.14 c. c. toxine 5+ 5-^0 
1 c. c. antitoxic horse 
serum (NYBH. 310), 
subcutaneously ; then 
daily for 15 days be- 
fore second inj ection, 
0.1 gm. CaClg by 
mouth. 
Days. 
104 
6 c. c. normal horse 
(roan) serum, in- 
traperitoneally. 
Marked symptoms. 
As'will be seen from the above, the guinea pigs which received 0.1 
gm. of CaClg for three days previous to the second injection of serum 
reacted in the usual manner, 2 of them dying in a few minutes, and the 
other two had severe symptoms. 
Of those which received 0.1 gm. CaCla daily for twenty days before 
; being given their sensitizing dose and then every other day for four- 
teen da}"s before they were given the second dose of serum, none showed 
any marked resistance. 
Of those that were sensitized first and then given 0.1 gm. CaClg for 
the fourteen days previous to the second dose, 5 out of 8 died in spite 
of the fact that 1 received only 3 c. c. of serum. 
I It is, therefore, quite plain that, while CaClg ma}^ modify the occur- 
' rence of rashes in children following a single injection of serum, it 
I does not influence to any marked extent the toxic effect in guinea pigs 
|] • of a second injection of serum given fourteen days after the first injec- 
tion. 
[ FREEZING DOES NOT DESTROY THE TOXIC PRINCIPLE. 
ji I Some normal horse serum (roan) was frozen hard at 15° F., then 
i ■ thawed at room temperature, and found toxic when injected into a 
I \ sensitized guinea pig. For example: 
i Xo. 
First injection. 
Interval. 
Second injection. 
Result. 
i 
Days. 
6 c. c. normal horse 
(roan) serum, 
frozen hard in 
brine, then 
thawed at room 
temperature, in- 
traperitoneally. 
Severe symptoms. 
5329 
0.22 c. c. toxine no. 7+ 
c. c. antitoxic 
horse serum (Nath, 
XIV), subcutane- 
ously. 
13 
i 
i, ' 
