THE CHINESE WHITE WAX INSECT. 
BY PROFESSOR B. SILLIMAN. 
We find the following note on this insect (a species of Coccus) 
in an interesting volume by T. T. Cooper.* Chemists have long 
known the so-called ‘‘ vegetable wax,” ‘Chinese wax” or “pela,” 
also called ‘‘ vegetable insect wax,” or ‘vegetable spermaceti,” 
but we have had no definite knowledge before of its history or 
mode of production. 
It was generally stated to be produced on certain trees by the 
puncture of a species of Coccus. Byt Mr. Cooper supplies us 
with the first definite statement we have seen of what proves to 
be an extensive, and to us novel, industry. Unfortunately, he 
does not appear to have secured specimens of the insects produc- 
ing it, nor does he give us more definite information of the plant 
on which they feed than that it resembles our privet. 
It may be interesting to non-chemical readers to know that this 
insect wax is a definite compound somewhat resembling spermaceti 
in appearance but not in composition, being a Cerotic ether known 
as Cerotate of Ceryl of the formula C® H™ O?. It is crystalline, 
and of a dazzling whiteness like spermaceti, but more brittle and 
of a more fibrous texture. It does not completely saponify by 
boiling in potash water, but is completely decomposed when melted 
with potash, yielding cerotate of potassium and hydrate of ceryl. 
It is consumed in China for candles and also as a medicine. It 
melts at about 118° F. It does not appear clearly from the state- 
ments of Mr. Cooper, whether this wax is secreted by the insect 
or is not rather an exudation from the stems of the trees punc- 
tured by the insect. Mr. Cooper plainly favors the former suppo- 
sition; but other writers of more pretensions to science entertain 
the opposite view. The plant on which the Chinese Coccus lives 
is stated to be Ligustrum lucidium. 
There are several sorts of vegetable wax well known to chem- 
ists and new to commerce, and we find it stated by Rev. Justin 
Doolittle in his “Social life of the Chinese” that the “vegetable . 
*Travels of a Pioneer of Commerce in siden Tail and Petticoats, on an overland Jour- 
ney from China toward India. By T. T. Coo London. Murray, 1871. 8vo, pp. 471. 
(683) 
