262 APPENDIX. 



gist, which is the carbonate of lead with a small admixture 

 of sulphuret of lead. 



" Crystals of the sulphato-tri-carbonate of lead have been 

 obtained from some of the diggings in Wisconsin. 



" Manganese, a metallic oxide, useful in various manufac- 

 tures, w^as found (but not in a pure form, nor in very large 

 quantities) among the earthy materials in the fissures of the 

 cliiT limestone. 



'* In some of the richest lead mines, very fine specimens 

 of cr}^stallized iron pyrites are associated with the sulphuret 

 of lead — some of it (capillary pyrites) brilliant and delicate 

 beyond any I had ever before seen. It is composed of fasces 

 or clusters of silk-like threads, of a pale golden-yellow color, 

 which may be readily separated with the point of a knife. 



SOILS. 



" An item in my instructions required me to report ' such 

 facts as will serve to convey some idea of the value and pro- 

 ductiveness ' of the district under consideration. 



" In obedience to this instruction, I have analyzed, with 

 care, the soils of Iowa and Wisconsin ; and the result of this 

 analysis, extended to fifteen different specimens selected from 

 the various parts of the district, is truly remarkable. 



*' It is a common, and usually a correct remark, that 

 mineral regions are barren and unproductive. ' If a stranger,' 

 as Buckland has well expressed it in the opening to liis 

 Bridgewater Treatise, * if a stranger, landing at the extremity 

 of England, were to traverse the whole of Cornwall and the 

 north of Devonshire, and, crossing to St. David's, sliould 

 make the tour of all North Wales, and passing tlience 

 through Cumberland, by the Isle of Man, to the southwestern 

 shore of Scotland, should proceed, cither by the hilly region 



