CARBOLIC AND CRESYLIC ACIDS. 269 



which Mr. Crookes observes, nothing appears more 

 perfect upon noxious vapours and septic germs, 

 " Could we always rely upon the presence of a suffi- 

 cient amount of either of these bodies no other purifier 

 would be needed." The utter impossibility, however, 

 of obtaining an adequate and continual supply over 

 an area of any extent is obvious. The great objection 

 to the use of disinfectants which act by oxidation, 

 Mr. C. finds in the fact, that the foetid odours and 

 gases in a given area, which are, as regards cattle 

 plague, perfectly harmless, are the first to be over- 

 come, while the actual virus of the disease, the par- 

 ticles of bioplasm which are altogether inodorous in 

 themselves, are the last to be attacked by these 

 vapours. Mere deodorization, therefore, is of no effect, 

 and affords no protection whatever. 



Of Carbolic and Cresylic Acids. Carbolic and 

 cresylic acids have great similarity in odour and 

 other properties, though distinct bodies. A white 

 crystalline, solid, pure, carbolic acid, melts at 34 C. 

 and is distilled at 180 C. Cresylic acid is a liquid, 

 and boils at 203. In the opinion of Dr. Angus Smith, 

 who conclusively proved that the putrefactive decom- 

 positions in soils which produce malaria do not occur 

 in the presence of very minute quantities of carbolic 

 acid, the antiseptic properties of cresylic acid rival, if 

 if they do not surpass, those of carbolic acid. 



The great value of carbolic acid as an antiseptic, 

 is said by some to be due simply to its affinity for 



