1881.] 



MICROSCOPICAL JOURNAL. 



85 



destroyed the organism found in the 

 virulent liquid of fowl-cholera sub- 

 jects, and that during this period 

 the virulence became progressively 

 weaker, causing a milder form of 

 disease, until, towards the last, and 

 while the organism still retained its 

 vitality, its virulence was entirely lost. 

 Charbon virus was then investigated 

 in the light of these facts. It was 

 evident that the effect of atmospheric 

 oxygen must be tried upon the rods, 

 for the spores were known to retain 

 their virulence unchanged for years. 

 To prevent the formation of spores, 

 the cultivations were made at a 

 temperature of 42° to 43° C, at which 

 point the organism multiplies by 

 division of the rods without the 

 formation of spores. Such a cultiva- 

 tion after standing a month in con- 

 tact with pure air loses all vitality, 

 and the organism transferred to fresh 

 liquid is no longer capable of repro- 

 duction ; the day before, however, and 

 every preceding day its vitality was 

 still retained, as was proved by its 

 growth in such new cultivations. The 

 virulence is entirely lost after the 

 first eight days that the bacillus is 

 kept at this temperature, and during 

 these eight days the virus passes 

 through progressive degrees of atte- 

 nuation. When a bacillus was thus 

 obtained which had lost all virulence 

 for the Guinea-pig, rabbit and sheep, 

 it was found that its powers might be 

 restored by cultivating it in the bo- 

 dies of certain animals. It would still 

 destroy a Guinea-pig but one day 

 old, though it had no effect on one 

 of six days, and by passing it' through 

 several successions of the former, it 

 was soon able to destroy animals 

 three to four days old, then those a 

 week, a month or several years old, 

 and, finally, the sheep itself. The 

 organism had entirely regained its 

 original activity. 



Having reviewed the recent investi- 

 gations of charbon, somewhat hurri- 

 edly it is true, it must be admitted 

 that there is no contradiction, no in- 

 consistency to be found in them ; we 



see a rapid increase in our knowledge 

 of the pathogenic agent, which prom- 

 ises much for the future in regard to 

 the whole class of the contagious dis- 

 eases ; but this advance has directly 

 followed from a study of the Bacillus 

 anthracts. The obscure points in re- 

 gard to the preservation of the virus, 

 its introduction into the body and its 

 action on the organism have been 

 made perfectly intelligible by the 

 germ theory, and it is impossible to 

 explain them on any other hypothesis. 

 Before concluding, and at the risk 

 of repetition, I offer the following 

 facts which prove the pathogenic 

 action of the B. anthracis. 



1. The one-hundredth cultivation 

 of the B. anthracis in a harmless 

 liquid, if made under favorable con- 

 ditions, is as virulent as the fresh 

 charbon-blood. 



2. When the B. anthracis is re- 

 moved by passing virulent liquids 

 through a plaster filter, these liquids 

 lose their activity. 



3. Virulent matters containing rods 

 only, lose their activity in a few days 

 if dried. 



4. Such matters containing spores 

 retain their activity an indefinite 

 time when dried. 



5. Virus containing rods only, soon 

 loses its activity if deprived of 

 oxygen. 



6. If these rods have formed spores, 

 the activity is retained indefinitely, 

 though deprived of oxygen. 



7. Putrefaction destroys virus which 

 does not contain spores, if the access 

 of oxygen is restricted. 



8. When there is sufficient access 

 of air to allow formation of spores, 

 putrefaction has no effect on the virus. 



9. Virulent liquids containing rods 

 alone, lose their activity by being 

 largely diluted with distilled water. 



10. The addition of water has no 

 effect on the virulence of liquids con- 

 taining spores. 



11. Virulent liquids, in which the 

 bacillus has not formed spores, lose 

 their activity in a few days if kept at 

 8°C. 



