273 



Professor of Chemistry in the Medical Department of the 

 University of Pennsylvania, a member of this Society, who 

 died on the 15th inst., at the age of 50 years. 



Dr. Charles M. Wetherill presented for the Transactions a 

 paper entitled " Chemical Examination of two Minerals from 

 the neighbourhood of Reading, Pennsylvania; and on the oc- 

 currence of Gold in Pennsylvania;" which was referred to a 

 Committee, consisting of Prof. Frazer, Dr. Bridges and Mr. 

 Trego. Remarks on the paper were made by Prof. Boye, 

 Mr. Trego, Prof. Frazer and Mr. Peale. 



The following is an abstract of this paper: 



Molybdenite. — Which is found in abundance at the Zion Church, 

 Alsace, in the neighbourhood of Reading. The specimens analyzed 

 were given me by Dr. BischofFand Mr. Keim. The mineral occurs 

 impure in mass, and of considerable purity in plates and scales ; in a 

 quartz matrix, presents the ordinary appearance of the mineral. 

 Hardness, 1. Density, 4.52. The analysis gave the following per 

 centage composition : 



Water, 0.297 



Sulphur, ■ - - 38.198 



Silica, 2.283 



Perox. Iron, .... 3.495 



Molybdenum, ... - 55.727 



100.000 



Zircon. — Found in the mineral spring valley behind Reading, 

 and at a locality 8 or 9 miles from Reading, N. E. of Pricetown. Is 

 imbedded so firmly in a matrix of magnetic iron ore, that the crys- 

 tals when detached leave a glazing upon the ore. Some of the 

 crystals are very large, one measuring 1 h inches by ^ inch by f 

 nearly. The planes and angles are all rounded off, as if subjected 

 to a semi fusion. One fragmentary crystal was found with its angles 

 and edges sharp and planes glass smooth. The colour, of chocolate 

 brown ; hardness, between 7 and 8 ; density, 4.595. The crystal 

 raised gradually to white heat does not exhibit phosphorescence; 

 becomes deeper in colour, gives off 0.35 per cent, of water, and 

 increases in density, which is, after the operation, 4.62, correspond- 

 ing to a condensation as 10.000 to 9.946. 



