656 CONDITIONS AFFECTING THE DEATH OF FUNGI. 



The more 

 intimate 

 nature of 

 attenuation. 



Attenuation 

 of the agents 

 of fermenta- 

 tion. 



Attenuation 

 of pathogenic 

 bacteria. 



Anthrax 

 bacilli. 

 Attenuation 

 by high tem- 

 peratures. 



chemical poisons are able to produce a permanent at- 

 tenuation. 



The vital phenomena which are in this way lost are, 

 as far as has yet heen ascertained, only the power of 

 producing fermentation and that of exciting disease. A 

 similar occurrence has not heen observed in the case of 

 the other functions and products of the tissue change 

 (pigment, ferments, &c.). The loss of the fermentative 

 or pathogenic properties is usually designated shortly 

 under the term " attenuation of the bacteria." Whether 

 at the same time there is diminished energy of growth 

 and of the whole phenomena of tissue change in the 

 pathogenic bacteria, thus explaining the victory of the 

 cells of the body, or whether it is only one of the vital 

 phenomena which is of importance in the warfare with 

 the cells of the body, namely, the production of a poison, 

 &c., which is acted on by the noxious agent and destroyed 

 for a considerable time, can only be decided as the result 

 of further investigations. 



Attenuation of the pathogenic mould fungi has not as 

 yet been observed ; see the above-mentioned experiments 

 by Frankel, p 126. 



As regards the attenuation of the fermentative bacteria 

 we have observations by Fitz. The anaerobic bacillus 

 butyricus could be so altered by heating it for five hours 

 at a temperature of 90 C., or for seven hours at 84 C., 

 that it no longer furnished the characteristic fermen- 

 tative products in suitable materials although it multi- 

 plied actively. In like manner the agent of butyric 

 fermentation isolated by Fitz at a later period (p. 388), as 

 well as the bacillus Fitzianus, lost readily the power of 

 producing fermentation, but also readily regained it. 



The attenuation of pathogenic bacteria has as yet been 

 successful in the case of bacillus anthracis, the bacillus 

 of symptomatic anthrax, the bacillus of fowl cholera, the 

 bacillus of swine erysipelas, and the as yet unknown ex- 

 citing agent of hydrophobia. 



The phenomenon of attenuation has been most accu- 

 rately studied in the case of the anthrax bacilli. The 

 employment of high degrees of temperature has proved 



