166 BACTERIOLOGY. 



soluble in water, and has, therefore, little value. 

 Many methods are used for bringing it into solution 

 so as to make use of its powerful disinfecting prop- 

 erties. With equal parts of crude sulphuric acid it is 

 a powerful disinfectant, but it is, of course, strongly 

 corrosive. An alkaline emulsion of the cresols and 

 other products contained in " crude' 7 carbolic acid 

 with soap is called creolin. It is used in 1 to 5 per 

 cent, emulsions. It is fully as powerful as pure car- 

 bolic acid. Lysol is similar to creolin, except that it 

 has more of the cresols and less of the other products. 

 It and creolin are of about the same value. 



Tricresol is a refined mixture of the three cresols 

 (meta-, para-, and ortho-). It is soluble in water to 

 the extent of 2.5 per cent., and is about three times 

 the strength of carbolic acid. 



Aniline Dyes. Some of these colors possess marked 

 germicidal qualities. According to observers, methyl- 

 violet (pyoktanin) and malachite-green destroy the 

 typhoid bacillus in bouillon cultures in the proportion 

 of 1 to 200 in two hours'* exposure, and the pyogenic 

 cocci in less. In 1 to 100,000 solutions they are said 

 to retard the development of bacteria. 



Oil of turpentine, 1 to 200, prevents the growth of 

 bacteria. 



Camphor has very slight antiseptic action. 



Creosote in 1 to 200 kills many bacteria in ten min- 

 utes; 1 to 100 failed to kill tubercle bacilli in twelve 

 hours. 



Essential oils: Cardiac and Meumir found that the 

 essences of cinnamon, cloves, thyme, and others killed 

 typhoid bacilli within one hour. Sandal- wood required 

 twelve hours. 



