276 



GENERAL OBSERVATIONS ON 



reflected on the subject, that the abstract value of a 

 lode in America can in no way be determined by 

 the assay of a piece of ore in England, particularly 

 when it is knov/n that specimens of ores are often 

 sent from South America as samples of lodes from 

 which they never were extracted. However, upon 

 the spot a calculation may be made of the probable 

 produce of the mine; and in Cornwall, where the 

 expenses of the mine are known and certain, it is 

 on this calculation that almost all the speculation 

 of the enterprise depends. For the riches of lodes 

 being subject to sudden variations, they may in- 

 crease or diminish in a surprising degree ; still the 

 calculation rests in Cornwall upon as fair a basis as 

 those which are made on the duration of human 

 life, or the insurance of ships, &c. &c. But in 

 South America the case is widely different; for 

 besides the value of the produce of the mine, it is 

 necessary to determine what will be the probable 

 expense of working it, in order to weigh or compare 

 the one with the other ; and the absolute necessity 

 of this, which is always done in mining, farming *, 



* No one would venture to say how much an unknown estate 

 is worth per acre, merely from an inspection of a box of earth ; 



