184 EXPEDITION TO THE 



the impression that it is in place, as we are informed that 

 it " is found in detached pieces and solid masses, in veins 

 and beds in red clay, and accompanied by sulphurate 

 (sulphate?) of barytes, calcareous spar, blende, iron py- 

 rites, and quartz."* Now, that all the indications men- 

 tioned by those who have seen these mines, justify a be- 

 lief that the lead is not in its original site, we consider as 

 satisfactorily proved. That the lead ore as well as the ac- 

 companying minerals, must be out of place, is equally ap- 

 parent, from the circumstance, that while the clay is said 

 to repose upon the limestone, the ore is not stated to have 

 ever been worked in this rock. We are told, that " the 

 greatest proportion of lead ore is, however, found imbed- 

 ded in, and accompanied by, the sulphate of barytes resting 

 in a thick stratum of marly clay, bottomed on limestone 

 rock. The rock is invariably struck at a depth of from fif- 

 teen to twenty feet, and puts a stop to the progress of the 

 miner in a common way. To go further, it is necessary to 

 drill or blast, and this creates an expense which the gene- 

 rality of diggers are unwilling to incur, if not unable to sup- 

 port"! Again, we find " in digging down from fifteen 

 to twenty feet, the rock is generally struck ; and as the 

 signs of ore generally give out on coming to the rock, 

 many of the pits are carried no further."J Finally, in 

 his visit to Dubuque's lead mines, performed in the year 

 1820, Mr. Schoolcraft observed, that the ore " had been 

 chiefly explored in alluvial soil;" though he at the same 

 time states, that " it generally occurs in beds or veins."§ 

 From the specimens which we have seen, as well as from 



• View of the Lead Mines of Missouri. New York, 1819. p. 67. 



flbid, p. 69. + Ibid, p. 108. 



§ Schoolcraft's Narrative Journal of Travels, 8cc. p. 344. 



