THE BACILLUS OF TETANUS. 393 



can readily be appreciated (Lambert). What the true 

 composition and constitution of the tetanus poisons are 

 is unknown. It has been shown, however, that it pos- 

 sesses neither the characteristics of an alkaloid (ptomain) 

 nor of an albuminous body (toxalbumin); it is largely 

 precipitated from fluids saturated with ammonium sul- 

 phate. 



The quantity of the toxin produced varies, even 

 when derived from one and the same culture, according 

 to the age of the culture, its composition, reaction, etc. ; 

 and partly it is due to the extreme sensitiveness of the 

 toxin, which cannot bear keeping any length of time or 

 exposure to light, being sensibly affected by most chem- 

 ical reagents and destroyed by heating to 55 to 60 C. 

 for any length of time. It retains its strength best in 

 the dry state. 



Some authors (Kitasato and Sanfelice) have main- 

 tained that the tetanus cultures retain their viru- 

 lence unaltered; others, again, have observed consider- 

 able alteration in toxicity. Righi, for instance, has 

 observed that the tetanus bacillus cultivated under 

 aerobic conditions may entirely lose its virulence. 

 Certain chemical agents also produce on cultures of the 

 tetanus bacillus an attenuation of virulence, if only a 

 temporary one. 



The Action of Tetanus Toxin in the Body. The parts 

 first to be affected with tetanus are in about one- third of 

 the cases in man, and usually in animals the muscles 

 lying in the vicinity of the inoculation for instance, 

 the hind foot of a mouse inoculated on that leg is first 

 affected, then the tail, the other foot, the back and 

 chest muscles on both sides, and the forelegs, until 

 finally there is a general tetanus of the entire body. 



