236 PASSIVE IMMUNIZATION 



market for examination at the hygienic laboratories of the Public 

 Health and Marine Hospital Service. 



In the United States diphtheria antitoxin is now marketed in 

 500, 1000, 2000, 3000, 4000, 5000, and 10,000 unit doses. 



The Injection. The injections are usually given into the loose 

 subcutaneous tissue between the shoulder-blades, into the abdominal 

 walls, or into the district overlying the triceps. The skin should be 

 scrubbed with soap and water and then with alcohol, or, as is now 

 also advised, merely painted with tincture of iodin about the point 

 of injection. If a separate syringe be used this should, of course, be 

 sterilized by boiling, but in the United States the manufacturers 

 now send the antitoxin out in separate syringes which are already 

 sterile and ready for immediate use. 



Of late it has been suggested that a more powerful effect may be 

 secured if the antitoxin is administered intramuscularly, or, still 

 better, intravenously. To this there can be no objection if the 

 amount of preservative that is thus injected at one time remains 

 within the limits of the permissible dose. In Heubner's clinic 18 c.c. 

 of serum containing 0.5 per cent, carbolic acid have thus been injected 

 at one time and the dose repeated within twenty-four hours. With 

 us, in the United States, where no preservative is frequently used, 

 even this objection does not exist. The advantage of the intra- 

 venous over the subcutaneous method of administration has been 

 clearly shown by Berghans, who found in the animal experiment that 

 whereas 40 units of antitoxin were necessary to prevent the death 

 of a guinea-pig when given subcutaneously, 0.08 was sufficient when 

 injected directly into the circulation, the amount of toxin having 

 been the same in both instances. The importance of resorting to 

 this method of administration is further emphasized by the obser- 

 vation made in the Danish Serological Institute that following the 

 subcutaneous use of the antitoxin this does not reach its maximum 

 in the circulation until the second or third day. Eckert thus very 

 properly insists that the intravenous method is the method par 

 excellence to be employed, and that with its general adoption the 

 death-rate from diphtheria will be lowered still farther (see below). 



Dosage and Uses. In the treatment of diphtheria by antitoxin 

 it is important to bear in mind that the quantity of toxin that is 

 produced and likely to be absorbed is, ccsteris paribus, the greater 

 the longer the duration of the disease, and that the union of the 



