>0^ 



fa 



22 On the disappearance of the Ice on Lake Champlain, 



4>*4. 



it on a strainer covering a cylindrical vessel which is placed in a 

 cauldron of boiling water; the wax is received into the former 

 vessel, and on congealing is ready for the market. The Pe-la or 

 while wax in its chemical properties is analogous to purified bees- 

 wax, and also spermaceti, but differs from both, being in my 

 opinion an article perfectly sui generis. It is purely white, trans- 

 parent, shining, not unctuous to the touch, inodorous, insipid, 

 crumbles into a dry inadhesive powder between the teeth, with a 

 fibrous texture, resembling fibfous calc-spar; it melts at lOO'^ Fah., 

 is insoluble in water, dissolves in heated essential oils, and is 

 scarcely affected by boiling alcohol, the acids, or alkalies. 



The aid of analytical chemistry is needed for the proper eluci- 

 dation of this most beautiful material. Tbere can be no doubt it 

 would prove altogether superior in the arts to purified beeswax. 

 On extraordinary occasions the Chinese employ it for candles and 

 tapers. It has been supposed to be identical with the white lac 

 of Madras; but as the Indian article has been foimd useless in the 

 manufacttire of caudles,* it cannot be the same; it far excels also 

 the vegetable wax (Myrica cerifera) of the United Stales. 



Is this substance a secretioti ? There are Chinese who regard 

 it as such, some representing it to be ihe saliva and others the 

 excrement of the insect. European writers lake nearly the same 

 view, biu the best aiuhorities expressly say ihat this opinion is 

 incorrect, and that the animal is changed into wax. I am inclined 

 to believe that the insect undergoes what may be styled a cera- 

 ceous degeneration, its whole body being permeated by the pecu- 

 liar produce in the same manner as the Coccus cacti is by carmine. 



Its cost at Ningpo varies from 22 to 33 cents per pound. 



The annual produce of this humble creature in China cannot 

 be far from 400,000 pounds, worth more than '$100,000. 



I^ingpo, Auj^ust, 1850. . . 



Art. V. — On the suddeyi disappearance of the Ice on Lake 

 Champlain, at the breakintf trp of Winter ; by Rev. Zadock 

 Thompson, of BarliugtoUj Vermont. 



'i 



The vanishing of th^ ice on Lake Champlain in spring is at 

 times so sudden, as to strike general observers with much sur- 

 -'^ p^se. But, for myself, although I have lived thirty years upon its 

 shores, where I have had a full view of its broadest part, and 

 where I have watched its closing in winter and its opening in 

 spring, with no inconsiderable interest, I have not in that' time 

 -witnessed anything, in relation to the phenomenon above men- 

 tioned, which has appeared to me either mysterious or very won- 

 <ierful. In the last fifty years there have been a/e\v cases (cer- 



* Dr. Pearson s l*hilosopIiical Tmnsaotions, voL xxi 



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