70 UTILIZATION OF MINUTE LIFE. 



substance was exhibited at the French Exhibition of 

 1855, but we have as yet no details concerning the 

 insect that produces it. 



All the insects of the genus Coccus contain a 

 considerable amount of grease, from which stearine, 

 the element of our modern ' ' wax- candle s," has been 

 extracted ; moreover, Berzelius extracted from 

 Coccus polonicus the acids which are contained in 

 butter ; and it is probable that butyric acid exists in 

 the whole genus. 



The latest information we have concerning the 

 spermaceti Coccus of the Chinese we owe to M. 

 Stanislas Jullien, who ascertained in 1840 that these 

 insects were cultivated indefatigably by the Chinese, 

 on three different sorts of plants, with equal suc- 

 cess ; namely, the plant they call nint-cliing, which 

 M. Brogniart tells us is the Rhus succedanea ; the 

 tong-tsing, which Thunberg says is Ligustrum gla- 

 brum ; and the goukin, a plant which grows in damp 

 places, and is probably the Hibiscus Syriacus, or 

 belonging to the same family as the latter. The 

 wax which is obtained from these trees abounds in all 

 the east and south provinces of China. It is col- 

 lected by scraping the trees in autumn, it is then 

 boiled in water, and strained through a cloth, after 

 which it is placed in cold water, when it becomes 

 solid, and then resembles soap-stone or steatite. 

 The young insects, according to M. Stanislas Jul- 



