SAPOCARBOL. 359 



134. Cresol or Cresylol, C,;H^(^^jj . — Preparation. — Cresol, a, 



methyl derivative of phenol (carbolic acid), is present in coal tar and 

 in wood tar. It is obtained in the distillation of tar at the same time as 

 phenol. Crude phenol is distilled and that which passes between 200° 

 C. and 205° C. is collected. It is an oil consisting in great part of 

 cresylol. 



Properties. — Cresylol does not combine so readily with alkalies as 

 phenol, and is less soluble in water. It is an oil which has much re- 

 semblance with carbolic acid in physical, chemical, and antiseptic 

 properties. 



Commercial Preparations containing Cresylol. — Cresylol is 

 rarely used as such, but mostly as its sodium derivative. It is an ingredi- 

 ent of the best known and most efficient insecticides. These are the 

 " sapocarbols," mixtures of crude cresylol and soap ; the " lysols," mix- 

 tures of tar [oil] and soap ; the "creolines," of analogous composition ; 

 " solutol,'' containing 15 per cent of cresylol, 45 per cent cresylate of soda, 

 in presence of an excess of alkali ; " solved," of analogous composition 

 but neutral ; " amylo carbol," consisting of 150 oz. of black soap, 160 oz. 

 of amyl alcohol, and 9 oz. of cresylol; " thymokresol," prepared in 

 America; "beech tar creosote," which contains along with phenol^ 

 phorol, gaiacol, cresol, much cresylol. The composition of these various- 

 insecticides differs greatly. They contain more or less cresylol accord- 

 ing to the source of the tars or the crude cresylols used in their pre- 

 paration. Like carbolic acid they all act on insects and on plants, 

 an action, however, which is more energetic but which varies much 

 from one product to another, according to the source of the cresylol. 

 There is thus much difference between the doses recommended as. 

 killing insects without injuring the plants. 



J35. " Sapocarbol." — This product, made in Brunswick, in Ger- 

 many,^ is a solution of homologues of carbolic acid in soaps. It is 

 made by heating a mixture of linseed oil, rosin, and potash, and the 

 oils collected in the distillation of crude carbolic acid, between 190° C. 

 and 205° C, oils which contain 10 per cent of cresylol, along with 

 xylenol, gaiacol, and other phenols. Alkali does not enter, except in 

 the small amount required to saponify the vegetable oils, in such a 

 way that the " sapocarbols " may be regarded as solutions of cresylols 

 in soaps. There are several brands of "sapocarbols". Their com- 

 position, very analogous to that of the lysols, is shown in Engler's 

 analyses. Table LXXIV gives the percentage of active ingredients, 

 which they contain. 



Properties. — " Sapocarbols " are neuti'al ; diluted with water they 

 yield an emulsion from which the aromatic hydrocarbides separate 

 more or less rapidly according to the amount of soap present. 



1 Tra7islator''s Note. — The manufacture of this class of goods is a British-born 

 industry which originated in the first instance in sheep-dip manufacture. Both 

 " Sapocarbol" and " Lysol" appeared on the Continent very late in the day, and 

 neither their composition nor manufacture is based essentially on any very new 

 principle. The only real distinctive feature is the proprietary name, and if every 

 proprietary mixture of this sort, however meritorious it might be in itself, were to 

 receive the special mention " lysol " and " sapocarbol " do here, the special literature 

 would be more than unwieldv. 



