ItitelUge/ice and Miscellaneous Articles. 149 



that of the diamond the writer of this notice is not aware ; nor has 

 he, at present, the means of ascertaining. 



It is worthy of remark, whilst considering this interesting ques- 

 tion, that the observation of Newton, which has usually been cited 

 merely as a sagacious conjecture of the combustible nature of the 

 diamond, is more precisely an anticipation of the conclusion, to 

 which the optical characters of this gem have led Dr. Brewster. 

 Sir Isaac infers, from the great refractive power of the diamond, 

 ♦' that it is probably an unctuous body coagulated." (See Phil. Mag, 

 vol. xvii. p. 197.) Such an inference, derived from an optical cha- 

 racter entirely distinct from that on which Dr. Brewster founds his 

 opinion, affords a strong additional reason for examining this view of 

 the question. 



The present state of the inquiry, then, respecting the origin of 

 the diamond, appears briefl}' to be as follows : 



Argument in favour of the vegetable origin of the diamond : 

 This gem is a form of carbon : of that species of matter which 

 constitutes the solid basis of all vegetable productions. 



It is certainly known to occur in nature, only in alluvial deposits, 

 and in a conglomerate rock containing fragments of older rocks ; 

 the evidence of its existence in mineral veins being confined to a 

 single specimen, and of course doubtful. Therefore we have no^;roo/' 

 that the diamond is originally a mineral substance. 



Sir I. Newton inferred that it was an unctuous body coagulated : 

 — Professor Jameson suggests the probability of its vegetable ori- 

 gin : — Dr. Brewster has ascertained that it presents analogies with 

 amber, a substance which we have every reason to believe is of ve- 

 getable origin, and also, that, like amber, it must once have been in 

 an extremely soft and compressible state ; whence he is led to con- 

 clude, that it originates from the slow consolidation of perhaps ve- 

 getable matter. 



Argument in favour of the mineral origin of the diamond : 

 The occurrence of carbon in the forms of anthracite and graphite 

 in mica-slate and other rocks believed to be of primary formation, ap- 

 pears to indicate that this species of matter is an original element of 

 the mineral kingdom, and existed anterior to the production of vege- 

 tables; and that, therefore, the carbon of the diamond is not Mcces- 

 mrily derived from vegetables. 



A specimen of diamond has been obtained, having for its matrix 

 a species of ironstone, known to occur in veins or beds on chlo- 

 rite slate ; a rock of early transition or probably primitive forma- 

 tion ; whence it may he inferred that this substance is an original 

 product of the mineral kingdom. 



The compressible state once possessed by the diamond, may (for 

 aught that has been advanced to the contrary,) have resulted from 

 the action of heat ; and, if so, the optical characters discovered by 

 Dr. Brewster, do not necessarily refer its origin to the vegetable 

 kingdom. E. W.B. 



HAUBOUK or KO-SI CHANG. 



The geographical i)osilion of the cluster of islands which form 

 the harbour of Ko-si Chang renders them of some importance to 



navigators, 



