380 Mr. B. C. Brodie on the Chemical Nature 



which, even in appearance, it more nearly resembles than any 

 other, is the purified cerine, that is, that cerotic acid of which, 

 mixed with certain other waxy matter, in a former paper, I 

 have shown the bees'-wax to consist. The accurate investi- 

 gation of the chemical nature of the Chinese wax has brought 

 to light certain curious chemical relations which exist between 

 these bodies, and led to the discovery of the alcohol of cerotic 

 acid. 



Cerotine. 



Chinese wax may be boiled for a long time either with di- 

 lute or with concentrated potash with hardly any signs of 

 saponification. If, however, it be melted with the hydrate of 

 potash, it is readily decomposed. This decomposition is best 

 effected in an iron basin over a large gas flame or gentle fire. 

 The mass, after the action, is soluble in boiling water, giving 

 a milky solution. From this solution two substances may be 

 procured ; an acid which may be combined with baryta by 

 precipitation of the soap with chloride of barium ; and a wax- 

 substance of another nature which is obtained by washing out 

 the baryta salt with any suitable solvent, such as alcohol, aether, 

 or naphtha. The soap, after precipitation by chloride of barium, 

 becomes perfectly clear, and, to obtain the wax-substance 

 which is not combined with the baryta, the baryta salt is first 

 to be separated by filtration from the fluid, then dried and 

 pulverized. It is convenient to effect, at first, a partial sepa- 

 ration of the salt from the other matter by washing it out with 

 a large quantity of boiling alcohol, and filtering the solution 

 hot through linen. After this operation has been two or three 

 times repeated, the substance, which passes through the filter, 

 is to be redissolved in the same alcohol and the solutions fil- 

 tered, in a similar manner, through paper, so as to separate 

 the small portions of the baryta salt which unavoidably pass 

 through the linen. The solution is much facilitated by the 

 addition of a small quantity of naphtha to the alcohol. If the 

 substance be purified by crystallization out of aether and ab- 

 solute alcohol, its melting-point will be raised to 79° C. Pre- 

 vious to analysis the substance is to be dissolved in absolute 

 alcohol and aether, and the solution filtered. This is a neces- 

 sary precaution, as the naphtha dissolves traces of the baryta 

 salt. The substance was analysed. 



I. 0*258 grm. gave 0*7725 C0 2 and 0327 HO. 



II. The numbers have been mislaid. 



III. 0'2G02 grm., another preparation, gave 07785 C0 2 

 and O^Sl HO, which give in 100 parts, — 



