APPENDIX. 39 



APPENDIX. 



[Extracts from the Author's Anniversary Address, 25 May, 1870.] 



DISCOVERT or DIAMONDS IN KEW SOUTH WALES — OPINIONS AS 

 TO THEIK OEIGIN. 



Connected with coal plants in transmuted deposits, there has 

 arisen another enquiry amongst ourselves as to the probable 

 origiu of the Diamond. How has the Diamond been produced, 

 and to what geological formation does it belong, are questions 

 which have had various replies. Although we may not be able 

 to solve the mystery, it may, perchance, be not iminteresting to 

 review the statements that have been put forth by different 

 authorities, now the public mind in Australia is excited by 

 accounts of increasiug discoveries of the precious gem in New 

 South Wales. 



It appears that I did not miscalculate, when, in 1860, I headed 

 a notice of five diamonds that had come into my hands, Neio 

 South Wales a Diamond Country (" Southern Grold Eields," p. 272) ; 

 for, up to the present time, several thousands have been brought 

 to light. In some valuable papers by Mr. Norman Taylor, 

 and in a report of similar character by Prof. Thomson of our 

 University, may be found a clear exposition of the phenomena 

 presented in the diamond field at Two-mile Flat, on the Cudge- 

 gong Eiver, which these gentlemen have recently explored and 

 described.* 



The opinions expressed by them are to the efii'ect that the 

 diamond district is limited to the presence of an ancient drift 

 deposit, covered generally by basaltic rocks, and that when found 

 in the river bed, or in alluvial soil, the diamonds are frequently 

 scratched and broken, whilst in the drift alluded to they are 

 found intact. And, at the points where they are thus found in 

 the river bed, they are so found in consequence of the tailings of 

 the miners having been washed thereto. 



The river having changed its course, the area referred to is 

 merely an alluvial space at one of those points. 



The general formations of more ancient date in the vicinity 

 are considered to be Upper Silurian, traversed by greenstone, 

 with overlying Carboniferous beds as outliers of more extended 

 strata. Mr. Norman Taylor has suggested that the diamonds 



* A paper subsequently read before the Eoyal Society will be found in the 

 Transactions for 1870. 



