xxi.] ANTISEPTICS. 261 



no more justifiable than to consider weak vinegar as such. 

 Perchloride of mercury in a solution of i in 300,000 is no 

 more capable of interfering with the life and functions of the 

 spores of bacillus anthracis than water or salt solution, for 

 the spores may be steeped in that solution for any length of 

 time, and yet on being transferred to a suitable medium they 

 grow and multiply splendidly, and when inoculated into 

 rodents they produce fatal anthrax with absolute certainty. 

 With my friend Dr. Blyth, Medical Officer of Health for 

 the Marylebone district in London, I have tried the action 

 of a number of substances in common use as antiseptics (e.g. 

 Cal vert's fluid, pure terebene, phenol 10 per cent., per- 

 chloride of mercury 0*1 per cent.) on the spores of bacillus 

 anthracis, exposing these in comparatively large quantities of 

 the above fluids (the two being well mixed) for several hours, 

 and then inoculating guinea-pigs with them (spores and anti- 

 septic). The animals died with symptoms of typical anthrax, 

 the blood teeming with the bacillus anthracis. 



These substances cannot therefore be considered germi- 

 cides for the spores of bacillus anthracis, any more than 

 water. 



In all these inquiries, particularly in those upon patho- 

 genic organisms capable of forming spores, the influence of 

 the substances must be judged not merely by their action on 

 the organisms, but also on the spores ; for, in this very case 

 of the bacillus anthracis, the bacilli taken from the blood of 

 an animal dead of anthrax are killed after an exposure of 

 say ten minutes to a solution of phenyl-propionic acid of the 

 strength of i in 400, or even i in 800, whereas the spores 

 of the bacilli (produced in artificial cultures) withstand com- 

 pletely exposure to this acid of any strength and for any 

 length of time. 



It is not my object to pass here in review all that has 



