ON BLACK WAX. 
13 
On spontaneous evaporation of the ether, a brown colouring-matter remained. 
This colouring-matter was easily soluble in bisulphide of carbon, in benzol, and 
in chloroform, and when heated with hydrate of potash turned black, and evolved 
ammonia. 
It fused very readily, and did not appear to be acted upon by a strong alco¬ 
holic solution of caustic potash. 
The black substance insoluble in ether was digested with chloroform, which 
immediately formed with it an opaque treacly fluid. 
Nothing appreciable was taken up from it by benzol, but it was quickly and 
entirely soluble in bisulphide of carbon, and likewise evolved ammonia when 
heated with caustic alkali. 
The first alcoholic filtrate was concentrated to a small bulk and let cool, to 
allow the cerotic acid to deposit. 
The precipitate was then filtered off. 
The cold alcoholic solution was evaporated to dryness, and the residual cero- 
lein weighed. The cerotic acid was got by difference. 
The results of the analysis are as follows :— 
Black Wax. 
Beeswax. 
Colouring matter, insoluble 
Average Composition. 
in ether . 
0-5142 
17-088 
Colouring matter, soluble 
Myricin . . . 73 
in ether . 
0-1280 
4-253 
Cerolein. 
0-4530 
15-054 
Cerolein ... 5 
Crude cerotic acid . . . 
1-9138 
63-602 
Cerotic acid. . 22 
3-009 
99-997 
100 
The identity of the cerolein with that obtained from beeswax is shown by its 
being acid to litmus, fusible at a very low temperature, soluble in ether, and 
quickly saponified by a hot alcoholic solution of potash. 
The quantity of cerotic acid obtained was too small, even had it been carefully 
purified, to admit of the determination of its atomic weight from the silver salt; 
but the derivation of it from a wax, its solubility in boiling alcohol, and the 
character of the precipitates which it gave with alcoholic solutions of acetate of 
lead and of nitrate of silver, all point to its identity with the cerotic acid of 
Brodie. 
This cerotic acid appears to exist in the wax in an uncombined state,—a fact 
to which Sir B. Brodie drew attention, as being without a parallel among any 
of the true fats. 
It may be remarked, that the separation of the cerotic acid from the other 
constituents is a particularly tedious process, and involves considerable delay. 
I have placed the average percentage composition of beeswax beside my own 
analysis, for the purpose of comparison. 
It will be seen that the percentage amounts of cerolein and cerotic acid are 
each about three times as great as in beeswax ; but it should be borne in mind 
that the proportion of cerotic acid varies in different samples of wax, and that 
it was entirely wanting in a specimen of Ceylon wax, and in a wax made by 
wild bees in Surrey (Brodie). 
The place of the myricin, i. e. the portion insoluble in alcohol, and which 
constitutes nearly three-fourths of the weight of common wax, is represented in 
the black wax by the two brown colouring-matters. 
It is to be regretted that, from the limited quantity of the wax operated 
on, I was unable to extract a sufficient amount of either colouring-matter for 
the purpose of submitting it to ultimate analysis. 
