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hear Caftleton, in Derbyshire ; refembles, in co- 

 lour and elafticity, cahout-chou, or Indian rub- 

 ber ; formed from naphtha or petroleum ; there 

 are many varieties ; fome in the ftate of afphal- 

 tum, by melting lofe their elaftic property, and 

 a quantity of gas is difengaged ; and the fubftance 

 xemaining refembles mineral pitch, or mineral tar. 



B. AMBER is one of the pureft bitumens, 

 confuting almoft entirely of a volatile oil, which 

 receives it's confidence from a peculiar acid (fuc- 

 cinic) and of a few earthy and coaly particles. 



Amber has been chiefly procured on the ftiores 

 of the Baltic. The yellow amber of Kcenigf- 

 berg has been lately difcovered by digging. It 

 is raifed 200 feet from the fea, where many fhafts 

 are funk, one of which is near 100 feet in depth. 

 The amber does not run in veins, but is found in 

 nodules, in a matrix of charcoal, below which there 

 are ftrata of fand. In the charcoal there are fome- 

 times little threads of amber. This feems to Chew 

 that the origin was volcanic, and that the amber 

 was accumulated by fublimation. 



a. Honey stone ; cryftallized in aluminiform oc- 

 tohedrals ; found in Thuringia, between beds of 

 bituminous wood, and is fometimes near an inch 

 in diameter; it is cryftallized in great mafTes, in 

 a double pyramidal form, with four fides ; it bears 

 a great refemblance to amber, but does not, like 

 that fubftance, become electric by rubbing ; by 

 Mr. Abich's analyfis it appears, that 50 parts of 

 this foflil are compofed of 8 parts of the carbonate 



