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amber is a bituminous substance, which, exuding in a soft and 

 nearly fluid state, from clefts in the earth where bituminous strata 

 exist, has, during its soft and tenacious state, inviscated and en- 

 veloped these different extraneous bodies. Against this opinion 

 there does not exist any objection, since it is not at all difficult 

 to conceive, that amber may be the solid form which the transparent 

 fluid naphtha assumes from inspissation under certain circum- 

 stances, as asphaltum may be considered to be the result of a similar 

 change effected on petroleum. 



It is true that I have considered it as probable, that petroleum, 

 an opaque and dark-coloured substance, is naphtha changed by 

 having suffered a degree of inspissation ; it may therefore appear 

 contradictory to suppose a transparent substance like amber to be 

 likewise the result of the inspissation of naphtha. But, as has been 

 already remarked with respect to the probable change of naphtha 

 into petroleum, the change is not effected merely by inspissation, 

 but by a separation and a change in the proportion of the consti- 

 tuent principles, hydrogen having escaped and charcoal having 

 been deposited. But most certainly there is nothing to contradict 

 the supposition that naphtha is also susceptible of a simple evapo- 

 ration, and consequent inspissation, similar to that which the fixed 

 oils undergo, in consequence of the long-continued application of 

 a gentle heat. 



If amber were gum or resin which has undergone the change of 

 bituminization, the matters which it contains should certainly also 

 have suffered a similar change. In the few pieces in my own pos- 

 session, as well as in all others which I have seen, except in one 

 instance, which I shall presently notice, the insects appear not to 

 have suffered the least change, even in their colours, which surely 

 must have been the case, had they been macerating in the softened 

 mass which contains them, during such a change ; although, from 



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