150 
MR. BRODIE ON CEROTIC ACID. 
Stance can be obtained melting’ at 70° and even 72° Centigrade, much harder than 
the residue of the wax, brittle, and slightly crystalline in its structure. If this sub- 
stance be boiled with a solution of caustic potash, it is saponified with the greatest 
facility. If the soap be decomposed by an acid, a baryta salt formed of the acid 
produced, and this salt be dried and washed out with ether, a certain portion of a 
substance will be taken up by the ether, which is but very slightly acted on by pot- 
ash. This is that substance which has been called cerain. I remarked that while 
from the residue of the wax this matter could be procured in considerable quantities, 
but a very small portion was obtained from the cerin ; a portion very small in rela- 
tion to the acids formed, and the quantity of which diminished with the purification 
of the substance. The analysis also of the unsaponified cerin agreed closely with that 
of the acid as separated from the baryta salt, and the melting-points only differed by 
four or five degrees Centigrade. Further experiment showed me that the same cerin, 
when boiled with caustic baryta, entered with the greatest facility into combination 
with that substance. These facts led me to suspect that the formation of the unsa- 
ponifiable body was due to the presence of a certain portion of the other substances 
of the wax, and was no true product of the decomposition of the cerin itself ; but 
that this substance was in truth no other than the acid itself existing, in a free state, 
in the wax. The experiments which follow are inconsistent with any other hypothesis. 
To prepare this acid bees’-wax is to be boiled out with strong alcohol, and the hot 
solution poured off from the undissolved residue. This operation may be repeated 
with advantage three or four times. The precipitates which are formed on the cool- 
ing of the alcohol are to be collected together and treated repeatedly with alcohol in 
the same manner as the wax itself, until the melting-point of the precipitate is raised 
to about 70° C., after which point the further purification of the body by this method 
of crystallization is extremely difficult. This substance is now to be dissolved in a 
large quantity of boiling alcohol, care being taken perfectly to effect the solution. 
To this solution is to be added a boiling solution of acetate of lead in alcohol, by 
which a voluminous precipitate is produced, which does not redissolve in the boiling 
mixture. The solution is to be boiled and filtered hot, by means of a hot water ap- 
paratus, from the precipitate. The precipitate while moist is to be taken from the 
filter, placed again in the flask, and boiled out with strong alcohol, and afterwards 
with ether. This operation is to be repeated several times until the fluid which passes 
through the filter carries no substance with it. The first portions of alcohol will 
contain considerable portions of a wax matter having a lower melting-point than the 
cerin, and having the appearance of the residue undissolved by the hot alcohol. 
The lead salt is to be decomposed by very strong acetic acid. The substance 
which separates, after having been well-washed with boiling water, is to be dissolved 
in absolute alcohol, and the solution, while hot, filtered. On the cooling of the 
alcohol a substance will crystallize out in fine granular crystals. This substance 
melts at about 78° C. It is highly crystalline on cooling from the melted state. Very 
