" SERUM ANTIDIPHTHERICUM IN THE PHARMACOPCEIA. 
The next edition of the United States Pharmacopoeia, being’ the 
eighth decennial revision, 1900, which is to appear shortly, will con- 
tain an antitoxic serum for the first time. The serum will be known 
officials as antidiphtheric serum or Se7nun cwiidiplithericvin and the 
unit Avill be recognized as that approved or established by the United 
States Public Health and Marine-Hospital Service. 
The official text, which has been kindly furnished by Professor 
Remington in advance, will be as follows: 
SERUM ANTIDIPHTHERICUM 
ANTIDIPHTHERIC SERUM DIPHTHERIA ANTITOXIN 
A fluid separated from the coagulated blood of a horse Equus cahal- 
lus Linne, immunized through the inoculation of diphtheric toxin. 
It should be kept in sealed glass containers, in a dark place, at tem- 
peratures between 1.5° and 15° C. (10° and 59° F.). 
A yellowish or yellowish-brown, transparent or slightlv turbid 
liquid, odorless or having a slightodor, due to the presence of the 
antiseptic used as a preservative. 
Specific gravit}u 1.025 to 1.010 at 25° C. (77° F.). 
Antidiphtheric Serum gradually loses its power, the loss in one 
year varying between 10 per cent, and 30 per cent. Each con- 
tainer should be furnished with a label or statement, giving the 
strength of the Antidiphtheric Serum, expressed in antitoxic units, 
the name and percentage b}- volume of the antiseptic used for the 
preservation of the liquid (if such be used), the date when the 
Antidiphtheric Serum was last tested, and the date beyond which 
it will not have the strength indicated on the label or statement. 
The standard of strength, expressed in units of antitoxic power, 
should be that approved or established b}^ the United States Pub- 
lic Health and Marine-Hospital Service. 
Average units. 
Immunizing dose for well persons. —500 units. 
The onh" other pharmacopoeia officiallv recognizing diphtheria anti- 
toxin is the Arzneibuch flir das Deutsche Reich (Pharmacopoea Ger- 
manica), fourth edition, 1900. The following is a translation of the 
German text: 
SERUM ANTIDIPHTHERICU3I — DIPHTHERIE-HEILSERUM. 
The blood serum of horses which have been immunized against the 
diphtheria poison. It is allowed to be sold in commerce b}’ author- 
. ( 79 ) 
