532 DR. HOLLAND'S LETTER. 



" Our present knowledge of the chemistry ' of geology, and physiology of veins, is 

 so limited and imperfect," says Dr. H., "that I shall not indulge in any speculations 

 further than to say, that I believe that gold originally was and is secreted from a chloride, 

 double of sodium or its sodium sulphides, together with any and all other metalliferous 

 arsenides, sulphurides and tcllurides ; and, contrary to Murchison, that it is not known 

 it was of any particular epoch, or period, especially the Silurian ; and in the face of every 

 metallurgist, from Lampadius to Phillips, that gold occurs "mineralozed," (using Van 

 Bonn's term,) by arsenic, sulphur and tellurium; and is, at the present day, in the persis- 

 tent true veins of every other metalliferous sulphide, combined with sulphur. 



" Every sulphide does not contain gold, it is true, but all persistent veins that ever 

 did, in the magnesian strata, still contain it, from New Brunswick and Canada to 

 Alabama, as I have found for the last nine years. There is denudation, geologically 

 speaking, at Point la Tete, N. B., Chaudiere mine, of Canada, in the gold counties in 

 Maine, and especially at the Bridgewater Vt., gold mine, as well as in Virginia, and 

 North and South Carolina. Yet still gold occurs in all the veins in variable quantities, 

 but enough generally, when its metallurgy is and shall be truly apprehended and 

 legitimately in operation." Aug. 29, 1859. 



"The 'bluish chloritic talc' is doubtless the absolute original repository of gold in this 

 and every other country." 



"This matrix, be it what it may prove chemically in its composition and affinities, is 

 not talc, nor exactly agalmatolite : it is mutating in this region, in all veins at ninety feet 

 permeated by vapor and water, and I have invariably noticed that when powdered, 

 and mixed, and ignited with nitrate of soda, that it becomes shining, stained mica, 

 and carries in many instances astonishing quantities of gold, resolved by this igni- 

 tion, when not a particle of gold or crystalline sulphide is to be detected by the eye 

 aided by the microscope." 



" Gold may have permeated this matrix as a double chloride, or sulphide, either in 

 vapor or solution. But when or where it came from, and was secreted, combined, or 

 diffused and precipitated, and is now by decomposition metallized the chemistry of 

 geology and the inorganic physiology of veins, must settle." Dec. 26, 1859. 



Dr. Holland has invented a new and ingenious method of separating gold from the 

 sulphides, which I was anxious to have applied to those of Vermont. The following 

 extract will show his willingness to do this, whenever he should return from the South. 

 This very desirable work we have not attempted, because no means have been placed at 

 our disposal for chemical investigations. But we give the extract below, to show where 

 this process can be satisfactorily performed, should it be wished : 



" I should be very glad of the opportunity of testing the Vermont sulphides for you 

 for gold, as I know they are auriferous as well as argentiferous, in their iron, lead and zinc. 



"When at Ludlow, Vt., I was very much surprised to find some very fine specimens 

 of sulphides of copper, cpllectecl from the summit of Mount Holly near ; but I had not 

 then leisure to visit the locality (1852) ; besides I was not then aware that all reformed 

 cupreous ores and sulphides, are more or less auriferous. The ores and sulphides I saw 

 are similar to the Brazilian ores in the Patent Office (1856) collected by our naval explor- 

 ing expedition, and to the Chilian, Peruvian, Carolinian and Georgian auriferous pyrites." 



