282 PATHOGENIC BACTERIA. 



their blood a distinctly potent and valuable antitoxic 

 substance. 



The method for the production of this tetanus anti- 

 toxic serum is very much like that for the diphtheria 

 antitoxic serum (q. z>.), except that a much longer time 

 is required for its production, that the doses of toxin are 

 of necessity smaller because its toxicity is greater, and 

 that trichlorid of iodin or Gram's solution will probably 

 need to be added to the toxin to prevent too powerful a 

 local reaction. Horses, dogs, and goats may be used. 



As tetanus cases are not very common, and the anti- 

 toxic serum when produced is not very stable in its prop- 

 erties, Tizzoni and Cattani have successfully prepared it 

 in a solid form, in which, it is claimed, it can be kept 

 indefinitely, shipped any distance, and used after simple 

 solution in water. Their method is to precipitate the 

 antitoxin from the blood of immunized dogs with alcohol. 

 Numerous cases of the beneficial action of this antitoxin 

 are on record. 



The strength of the serum is generally expressed 

 i : 1,000,000, i : 10,000,000, etc., which indicates that i 

 c.cm. of the serum is capable of protecting 1,000,000 or 

 10,000,000 grams of guinea-pig from infection. 



The experiments of Alexander Lambert show that a 

 protective power of i : 800,000,000 can be attained. 



As Welch has pointed out, the antitoxin of tetanus has 

 proved to be rather a disappointment in human medicine, 

 and also for the treatment of large animals, such as the 

 horse. The results following its injection, in combination 

 with the sterile toxin, into mice, guinea-pigs, and rabbits 

 are highly satisfactory, but the amount needed, in pro- 

 portion to the body-weight, to save the animal from the 

 toxin being manufactured in its body by bacilli increases 

 so enormously with the day or hour of the disease as to 

 make the dosage, which increases millions of times where 

 that of diphtheria antitoxin increases but tenfold, a matter 

 of difficulty and uncertainty. Nocard also calls atten- 

 tion to the fact that the existence of tetanus is unknown 



