3IO Veterinary Medicine. 



Serum Antitoxin Orrotherapy. Babes appears to have been 

 the first (1889) to use the serum of animals (rat) recovered from 

 tetanus in mitigating and curing tetanus in experimental cases. 

 An attempt on a well developed case in man failed. His-method 

 of preparing the serum is as follows: A horse of 900 lbs. (461 

 kgm.), is inoculated with a mixture composed of 0.5CC. toxin 

 (of which o.ooi mgm. kills a mouse) and 0.5CC. iodo-potassium 

 iodide, and then at intervals of four or five days of 2. see, 4, 5 

 and locc. of the iodine mixture. Then stronger mixtures are 

 used: first 2 parts of toxin to i part of the iodine mixture; dose 

 locc; then 3:1 dose locc; then 4:1 dose 5cc.; then 15:1 dose 

 locc. ; then 30:1 dose 25CC. ; and finally virulent cultures in pro- 

 gressively encreasing doses 10, 20, 30 and 50CC. One week after 

 the last injection icc. of the blood serum will antidote 50CC. of 

 toxin. Injection of toxin is however continued and the dose is 

 gradually raised to 2oocc. Eight or fourteen days after the last 

 injection the blood serum may be taken for protective purposes. 

 He has prepared antitoxin from cows in the same way, and 

 Brieger and Ehrlich have prepared it from the goat. Chickens be- 

 ing naturally refractory to tetanus toxin can bear large doses and 

 a potent antitoxin is more speedily secured from them. In the 

 case of the cow the milk is rich in antitoxin. 



Other methods of preparing au animal for producing the anti- 

 toxin have been resorted to as injecting it with a mixture of toxin 

 and antitoxin in increasing doses, or again injecting with a mix- 

 ture of toxin and thyroid extract in increasing doses. The ex- 

 tract of the normal thyroid contains a natural antitoxin. 



It may be fairly inferred that the antitoxin is not formed in the 

 nerve cells alone in their resistance to the toxin, biit also in the 

 thyroid, the liver (bile having an antitoxic action), and perhaps 

 in other organs or liquids. 



The blood of the immunized animal drawn through the steril- 

 ized cannula and aspirating syringe is coagulated in vessels set 

 on ice, and the serum when separated is mixed with 0.5 per cent, 

 carbolic acid and i per cent chloroform, and kept in the dark in 

 well closed bottles. It will usually keep for years. 



Early experiments with antitoxins showed that when mixed 

 with the toxin before injection it could be trusted to neutralize 

 it. Ehrlich, Tizzoui and Cattaui even claimed success in all ex- 



