THE UEAL MOUNTAINS. 71 



ia the district under consideration, including the low 

 regions extending from each flank of the Ural, to an 

 elevation whereby a change to a colder climate was 

 effected. To the general view of Baron Humboldt, that 

 the richest gold deposits are those which are derived fjom 

 ridges having a meridian direction, M. Erman is opposed ; 

 but Sir Roderick is of opinion that it is a fact that the 

 greatest quantity of gold ore has been obtained from 

 chains having a nearer relation to north and south than to 

 equatorial or east and west directions, due perhaps to the 

 general form of the chief masses of land, and the prevailing 

 strike of the palaeozoic rocks. . . . 



' Comparing California with the Ural, Sir Roderick 

 shows that there is a very great coincidence of mineralo- 

 gical structure, and that with these constants the same 

 results obtain ; the chief distinction consisting in the 

 apparently larger proportion of gold in the detritus of the 

 newly-discovered deposits in California than in those of 

 the (Jral. More recently. Sir Roderick and other geolo- 

 gists have observed a striking resemblance between the 

 geology of the Ural chain and that of the Blue mountain 

 ranges in Australia, which run, in a general line, not far 

 from the meridian, through 30 degrees of latitude in Tas- 

 mania and New Holland, and New Guinea, having their 

 highest points at an altitude of from 5000 to 6000 feet 

 above the sea ; with an axis of chloritic and talcose schist, 

 and quartzites, with occasional limestones of Silurian age, 

 in which occur metallic ores and gold in veins of quartz. 

 Moreover, granitic rocks of a comparatively younger age 

 break through them, As on the flanks of the Ural, the 

 carboniferous formation reposes, so in Australia occurs the 

 very same order of deposits. Sir Roderick, therefore, anti- 

 cipated the extraordinary discovery of gold in the Austrav. 

 lian continent, thinking it most highly probable that, 

 besides the lead and copper which exist in the Blue moun- 

 tain ranges, auriferous sands would be found in the rivers 

 flowing from them. In respect of other phenomena, the 

 dividing ranges of New Holland are similar to the Ural, 



