55 



Whereter there are mines, (subterraneous ex- 

 cavations), metals of some sort or other are pro- 

 duced; and it surely is not burthensorae to the 

 intellect to know lead ore from copper, or silver 

 from lead, or gold from iron, or diamonds from 

 pebbles. 



Permit me to advise the traveller to look in- 

 to the book of nature, which is always open, and 

 learn what he can. A little information on this 

 head may prove highly advantageous, as the 

 wealth of nations mostly depends on the produce 

 of their mines. It is earnestly to be recommend- 

 ed, wherever he goes, to bring from thence some 

 of the rocky substances, and if any other present 

 themselves, he should endeavour to possess him- 

 self of them, which he might examine at leisure, 

 with tlie simple instrument the blowpipe, the use 

 and mode of managing which is explained in a 



