PACKAnn] INSECTS OF THE PLANT HOUSE. 113 



Orange). The dark part is the insect, the pale portion the 

 cottony or woolly clown enveloping the eggs and young 

 larvae. The female is flat and scale-like, while the male is 

 two-winged. All these scale insects are closely allied to the 

 wax producing Coccus. 



Professor Silliman informs us, in the "American Natural- 

 ist," that it may be " interesting to non-chemical readers to 

 know that this insect Avax is a definite compound somewhat 

 resembling spermaceti in appearance, but not in compo- 

 sition, being a cerotic ether known as cerotatc of ceryl, of 

 the formula C^^ W°^ 0-. It is cr^-stalline, and of a dazzling 

 whiteness like spermaceti, but more brittle and of a more fi- 

 brous 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." Prof. Silliman quotes from a 

 recent book by C. C. Cooper (Travels of a Pioneer of Com- 

 merce in Pig Tail and Petticoats, etc., London, 1871) the 

 following interesting account of the cultivation of this wax 

 insect. " On the third day we entered the white wax coun- 

 try, so named from its producing the famous white wax of 

 Szchuan, which has been erroneously called vegetable wax. 

 This district was less undulating than that of the tea gardens, 

 and presented to the e3'e a view of extensive plains sur- 

 rounded by low hills. The plains were all under wax and 

 rice cultivation, the wax trees being planted round the 

 embankments of the small paddy fields, which were at most 

 thirty yards square. The country thus presented to the pass- 

 ing traveller the appearance of extensive groves of tree 

 stumps, each as thick as a man's thigh and all uniformly cut 

 down to a height of about eight feet, without a single branch. 

 The cultivation of wax is a source of great wealth to the 

 province of Szchuan, and ranks in importance second only 

 to that of silk. Its production is not attended with much 

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