THE VITAL PHENOMENA OF BACTERIA. 77 



come into practical use as disinfectants. Inci- 

 dentally the observation was made (which is in- 

 teresting as regards hypotheses of molecular 

 constitution), that ortho-phenol sulfonic acid 

 acts very strongly upon anthrax spores, but that 

 the para-compound, which is produced by heat- 

 ing the ortho-compound, does not. The differ- 

 ence in the action of these two compounds upon 

 the vegetative cells is not so great. Laplace 

 prepared mixtures of crude carbolic acid and 

 sulphuric acid which were very active, indeed 

 more active when they were made in the cold 

 than when made at a higher temperature. 

 This latter fact might favor the view that 

 in the cold the real ortho-sulfonic acids are 

 formed, while at the higher temperature only 

 the less active para-sulfonic acids appear, but 

 might also, as C. Frankel thinks, be explained 

 on the supposition that in the cold we obtain 

 only mixtures with sulphuric acids ; in the 

 warmth real sulfonic acids. Mixtures are in- 

 deed, as Rotter first showed, often more effective 

 than the individual components, but Biel has 

 found that as a matter of fact the sulfonic acids 

 of cresol are formed in the cold. It is an im- 

 portant fact, however, that in crude carbolic 

 acid, cresol (C 6 H 4 CH 3 OH), as well as phenol 

 (C G H 5 OH), is present in large quantities. Ac- 

 cording to C. Frankel, the former has a greater 



