39 
DRYING DOES NOT INJURE THE TOXIC PRINCIPLE. 
We have on hand a large quantity of dried antitoxic horse serum 
which has been prepared and preserved under special conditions for 
the preparation of the standard antitoxic unit. This serum was 
carefully dried under bacteriological precautions at a temperature 
below 37° C., as described in Bulletin Xo. 21 . a 
That such dried and redissolved serum still retains its toxic prop- 
erty is evident from the following experiment: 
G. P. No. 4376. Six c. c. antitoxic horse serum (B 1 + 12) injected into the peritoneal 
cavity. Symptoms; recovered. 
[Previous treatment: 19 days prior, inoculated subcutaneously with 0.22 c. c. toxine 
No. 7+ 2 1 o c - c - h Qrse serum (Natl. V. 7).] 
THE TOXIC PRINCIPLE CAN NOT BE SEPARATED BY PRECIPITATION AND 
DIALYSIS. 
We made several experiments to determine whether precipitation 
by ammonium sulphate and subsequent dialysis to remove the sul- 
phate and other inorganic salts would also remove the toxic principle. 
For this purpose we used antitoxic horse serum prepared and dialysed 
in accordance with Gibson’s method. * * * * 6 It is plain from the following 
experiments that precipitation and dialysis do not remove the toxic 
principle : 
G. P. No. 4104. Six c. c. antitoxic horse serum (NYBH A) injected into the peritoneal 
cavity. Dead in 5 minutes. 
[Previous treatment: 37 days prior, inoculated subcutaneously with 0.22 c. c. toxine 
No. 7+23-0 c . c . horse serum (Alex. 190).] 
G. P. No. 4506. Five c. c. antitoxic horse serum (Alex. A 203/NYBH) injected into the 
peritoneal cavity. No symptoms, c 
[Previous treatment: 25 days prior, inoculated subcutaneously with 0.19 c. c. toxine 
No. 7+1 unit horse serum (Standard B27).] 
G. P. No. 4513. Five c. c. antitoxic horse serum (Alex. A 203/NYBH) injected into the 
peritoneal cavity. Dead in 39 minutes. 
[Previous treatment: 26 days prior, inoculated subcutaneously with 0.19 c. c. toxine 
No. 7+1 unit horse serum (Standard B27).] 
EFFECT OF VARIOUS CHEMICAL SUBSTANCES UPON THE TOXIC PRINCIPLE OF 
HORSE SERUM. 
Various substances of widely different chemical nature were added 
to horse serum, in order to see whether any of them had the power 
of precipitating, oxidizing, or neutralizing the toxic property of the 
serum. The following substances were used: Succinic acid per- 
cRosenau, M. J.: The immunity unit for standardizing diphtheria antitoxin (based on 
Ehrlich’s normal serum); official standard prepared under the act approved July 1, 1902. 
Bulletin 21, Hygienic Laboratory, U. S. Public Health and Marine-Hospital Service. 
Washington, Government Printing Office, April, 1905. 
& Gibson, R. B.: On the practical concentration of diphtheria antitoxin. Am. med., 
vol. 10, 1905, p. 915. 
c Explanation of occasionalirregularities, p. 63. 
