THE BACILLUS OF TETANUS. ° 393 
can readily be appreciated (Lambert). What the true 
composition and constitution of the tctanus 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, ete. ; 
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 
aérobic 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 fovt, the back and 
chest muscles on both sides, and the forelegs, until 
finally there is a general tetanus of the entire body. 
