CHAP. VII. NEW WORKING OF MINES. 1?3 



of the sources of that subsequent supply of those 

 metals, on which the increase, the stationary 

 continuance, or the diminution of them mainly 

 depended. 



In the former part of this inquiry it has been 

 stated that, under the reigns of the earlier Roman 

 emperors, a new system of working the mines in 

 the imperial dominions had been introduced. 

 Instead of farming out the mines to avaricious 

 or negligent renters, the government took the 

 working of them into its own hands, and carried 

 on the several operations under the superintend- 

 ence of its own officers. If by this first step 

 there was no great gain to the newly installed 

 proprietors, it at least put a stop to that ruinous 

 system by which the best ores alone had been 

 taken away, and those of inferior quality left to 

 impede the operations of the succeeding ex- 

 plorers. It appears also to have introduced 

 more economical practices in the application of 

 the labour of the workmen. This was, however, 

 but a step which was soon followed by another. 



It was found no longer possible to conduct 

 the various operations in the mines and in the 

 buildings above ground, by which the roasting, 

 washing, and separating the minerals from the 

 ore were carried on by means of slaves. The 

 government was in possession of the mines, as 

 well as the land above and around them ; the 

 occupiers of the soil were a kind of adscripti 



