458 



INl'ECTIVK mSEASES. 



characteristic odour. In slightly alkaline broth, and peptone witli 

 (ilkaline reaction, in an atmosp]i(!)o of hydi'ogen, the gas formed 

 will be sufficient to break tho flask if it is sealed up. Kitasato 

 obtained his cultures from pus, by taking advantage of the resist- 

 ance of the spores to high tiiirip(^ratiir(is. By raising cultures 

 to 80° G. for threo-quartiji's of an hour, the micrococci and ))iicilU 

 in the inixod culture wen; destroyed, while tho spores of tlie 

 tetanus ))acilluK retained their vitality, arid then sub-cultures were 

 obtained in a pure state. The spores are said to be killed by 

 exposure to steiim for five minutes. A 5 piM- 

 cent, solution of cai'holic acid with '5 per eout. 

 of hydrocldoric, will destroy tlje spoi'es irj twO' 

 hours. Kitasato and Weyl obtained tetanin 

 from pure cultures of the. bacillus, Hi'iegei' 

 having previously ohtiiiiiiid it from impure 

 cultures. A tetano-toxin, indol and |)l](!nol, and 

 butyric ueid ;ij'e also found. Jir'iegc^r and 

 Fi'iinkel attribute the jiathogenie (iropertios to 

 a tox-albuiuin. These produets have beeti (h:- 

 scribed more fully in ii previous chapter (p. 41). 

 A pure-culture produces tetanus in a mouse 

 in twenty-fovu- lionrs, and I'abbits, gujn(!a-pigs, 

 and rats can also lie infected. No |ius forms 

 at the seat of inoculation, as after inoculation 

 of earth, but the spasms corniruince in the 

 muscles nearest to the seat of inoculation. A 

 trace of a broth culture will kill a guinea-pig, 

 the symptoms develojting in tlirei; days. 



Kitasato succeeded in inaking animals im- 

 mune to tetanus, and subsequently the discovery 

 was made that the blood in immune animals 

 Fio. 180,— PuKK-oui.- ^^"^ produce immunity in other animals, the 

 TUBE OK Tetanus explanation being that the toxic principle of 

 BACi;-ij IN Gbapk- ^jjg tetiinus bacillus induces the fornjation of 



SUOAK G KLATINE. , , .., . i ... i j. /? j_i 



Four days old. tetanus antitoxin; and it equal jiarts ot tho 

 (F BA N K K L AND seiTim of an immune animal, and a fatal dose of 

 Pkkiffbb.) tetano-toxin, are together injected into a healthy 



guinea-pig, tetanus will not follow, showing that the, vir'i.is has 

 been, neutralised. Tizzoni and Cattani found that blood from an 

 immunised dog was not only[capable of completely neutralising the- 

 toxic power of filtered cultures, but that the injection of the blood- 

 serum produced immunity in otherwise susceptible animals, except 



