228 Mr. B. C. Brodie's Investigation on the 



simple crystallization. By patience this may be accomplished. 

 The cerine analysed by M. Levvy melted at 62°-5 C. I have 

 stated that by means of alcohol this substance may be pro- 

 cured of a melting-point of 72°. If this substance of 72° 

 melting-point be repeatedly dissolved and crystallized out of 

 a large quantity, not of alcohol, but of aether, the melting- 

 point can be raised to 78°, in which state the substance is 

 highly crystalline, and has all the appearance of the acid as 

 procured by other means. 



0*25625 grm. of this gave 0-7435 C0 2 and 0'3005 HO, 

 which gives in 100 parts — 



Carbon . . . . 79" 13 



Hydrogen . . . 13*20 



Oxygen .... 7*67 



100-00 

 Both the melting-point and the analysis perfectly agree with 

 the melting-point and analysis of cerotic acid, which have 

 been already given, and with its formula. 



It is certainly a strange fact that the presence of this body 

 in the wax should so long have escaped the notice of chemists. 

 The wax however is a complex substance, and the cerotic 

 acid to be obtained in purity has to be separated from m^.ny 

 other bodies which disguise its nature and reactions. 



Should any chemist be induced to verify the results which 

 I have given, I must beg him also rigidly to observe the 

 methods I have laid down for the preparation and purification 

 of the substances, for errors which are slight in the analysis 

 of the substance and which neither the analysis nor melting- 

 point detect, become of great importance when the trans- 

 formations of the substance are investigated, and its atomic 

 weight is to be determined. 



The alcoholic extract, out of which the cerotic acid has 

 crystallized, contains yet another acid, although in very small 

 quantity. If to the solution an alcoholic solution of ace- 

 tate of lead be added, a precipitate of a lead salt is produced : 

 this salt is readily distinguished from the salt of the cerotic 

 acid as it is dissolved on boiling the alcoholic solution, out of 

 which, on cooling, it will separate in crystalline grains. This 

 substance is contained in very small quantity in the wax. It 

 resembles in appearance margaric acid. I have analysed this 

 acid and one of its salts. These experiments showed that it 

 approached margaric acid in its constitution : but I have 

 never been able to procure the quantity necessary to its suffi- 

 cient purification, and the analyses led to no conclusions as 

 to its formula which deserve to be recorded. 



