147 



of Odontopteris Brardii, and some probably new Odontopterides, 

 from the black schist, Portsmouth, R. I., and of various other fos- 

 sil vegetation, from Mansfield, Mass., and from Nova Scotia, with 

 a list of fossil vegetables from various American localities. 



Dr. C. T. Jackson exhibited specimens of Copper and 

 Zinc Ores, from Warren, N. H., considered by him to be 

 remarkable in their structure and appearance. 



The copper Pyrites occurs intermixed with crystallized Tremo- 

 lite, and brown mica, and takes the form of those minerals, being 

 fibrous in the Tremolite, and flattened into plates in the mica. 

 The black blende exhibits the same structure, and the iron Py- 

 rites is also impressed with the form of the fibrous Tremolite, also 

 crystals of an octahedral form, composed of yellow copper pyrites 

 and black blende. He remarked that this impressibility of one 

 mineral by another, seemed something like the influence of ex- 

 ample as exhibited in another department of science, and the 

 power of numbers was evidently perceptible in the compression 

 of the more sparse ores, amid these congeries of Tremolite crys- 

 tals and micaceous plates. 



Specimens of rich argentiferous galena, from Warren and 

 Shelburne were exhibited, those from the latter town being asso- 

 ciated with cuperiferous black blende, and beautiful crystals of 

 iron Pyrites. The lead from these ores contains from 4 to 5^ 

 pounds of silver per ton, a sufficient proportion to warrant its ex- 

 traction by cupellation. The mines are about to be wrought for 

 lead and silver. He exhibited also specimens of twisted crystals 

 of rutile or red oxide of Titanium, and bright green crystals of 

 Apatite or Phosphate of Lime, from the Warren copper mine, the 

 latter being a new mineral for that locality. 



Dr. Jackson also remarked upon a paper on the geology 

 of a portion of the White Mountains, by Professors W. B. 

 and H. D. Rogers, published in the American Journal of 

 Science, for May, 1846. 



He said that it was his intention, during his late visit to New 

 Hampshire, to have examined the spot, where, as stated by those 



