TETANUS. 379 



ever, their poison was not removed, or if the body-cells 

 were injured by the simultaneous introduction of lactic 

 acid or other chemical agents, the bacilli would imme- 

 diately begin to manufacture the toxin and produce 

 symptoms of the disease. 



The toxin is easily prepared, being readily soluble in 

 water. The most ready method of preparation is to 

 grow the bacilli in bouillon, keeping the culture-medium 

 at a temperature of 37 C, and allowing it to remain un- 

 disturbed for from two to four weeks, by which time it 

 will have attained a toxicity so great that 0.000005 c.cm. 

 will cause the death of a mouse. The toxin is very rapidly 

 destroyed by heat, and cannot bear any temperature above 

 6o°-65° C. It is also decomposed by light. The best 

 method of keeping it is to add 0.5 per cent, of phenol, 

 and then store it in a cool, dark place. It will not t 

 keep its strength very long under the best conditions. 



The purified toxin of Brieger and Cohn was surely 

 fatal to mice in doses of 0.00000005 gram. Lambert, 1 in 

 his comprehensive review of the use of tetanus antitoxin, 

 points out that this is the most poisonous substance that 

 has ever been discovered. 



Like most of the bacterial toxins, the tetanus poison is- 

 only effective when produced in or injected into the tissues 

 and absorbed directly into the circulation. It is harmless 

 when given by the digestive tract, Ramon 2 having ad- 

 ministered by the mouth 300,000 times the fatal hypo- 

 dermic dose without producing any symptoms. The 

 toxin seemed to pass out with the feces. 



The toxin has a very painful local action associated 

 with spasm of the muscular fibres with which it comes 

 in contact. Pitfield 3 injected it into the calf of his leg 

 and experienced the local effects of the poison for twelve 

 hours. 



By the gradual introduction of such a toxin into ani- 

 mals Behring and Kitasato have been able to produce in 



1 New York Med. Jour., June 5, 1897. 



* Deutsche med. Wochenschrift, Feb. 24, 1898. 



* Therapeutic Gazette, Mar. 15, 1897. 



