GEOLOGY. 325 



with the quartz, together with some sulphuret of iron, and a very few 

 small particles of gold : but whether gold or lead will here be found 

 in sufficient quantities to pay for working, is yet problematical." 



Gold in Australia.- -The actual production of the precious metal of 

 this new and wonderful gold field has thus far proved fully up to the 

 wildest calculations entered into in 1852. The ascertained yield of the 

 Melbourne mines to the 31st July, amounted to 53 tons weight, or 

 inexact Federal value, to $25,312,800! And at the Sydney mines 

 to Si 2,500,000.. A further sum of $5,000,000 is set down to Adelaide, 

 South Australia, though thence taken, for the most part, by miners from 

 the Melbourne district. The aggregate, therefore, stands thus : 



At Melbourne . . 53 tons .... $25,312,810 



At Sydney 26 " .... 12,500,000 



At Adelaide . . . 11 " .... 5,000,000 



Grand total . . . 90 " .... 42,812,800 



As considerable interest is felt at the present time concerning the 

 diffusion of gold over the earth's surface, it may be interesting to our 

 readers to be informed of the results of an investigation of that subject, 

 which is now being carried on at the Government School of Mines. So 

 far as that investigation has extended, Prof. Piercy states, that a sensible 

 and visible amount of gold has been extracted from every variety of 

 British and foreign lead, as well as every specimen of litharge, minium, 

 white-lead, and acetate of lead, which have been examined. It has 

 also been extracted in very sensible proportion from commercial 

 bismuth. Between thirty and forty determinations have already been 

 made. 



EARTHQUAKE INDICATOR. 



M. Ratio-Menton, a gentleman connected with the French diplo- 

 matic corps in the Argentine Republic, has recently communicated to 

 the Paris Academy of Sciences, by a letter addressed to the French 

 Minister of Foreign Affairs, a sure means of learning the approach of 

 an earthquake. According to this gentleman, the earthquake indica- 

 tor is nothing more than a magnet, to which is suspended, by magnetic 

 attraction, a little fragment of iron. Shortly before the occurrence of 

 an earthquake, the magnet temporarily loses its power, and hence the 

 iron falls. According to M. Ratio-Menton, the accuracy of this indi- 

 cative sign has been thouroughly tested by a highly educated Argen- 

 tine officer, Colonel Epinosa, during a residence of many years at 

 Arequipa, a region where earthquakes are very frequent. Independ- 

 ently of the authority of the communication, arising from the respect- 

 ability of the communicator, and from its being published in the 

 transactions of the French Academy of Sciences, the result is nothing 

 more than might have been suspected from theoretical considerations 

 of the alliance between electricity and magnetism. A disturbance 

 of electric power has long been known to be associated with earth- 

 quakes. 



