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American Institute, Polytechnic Association, ) 



Jane IQth, 1860. \ 



Professor Mason, Chairman. John Johnson, Esq., Secretary pro. tem. 



Peter Cooper read a paper on " The Currency," its management, its 

 past, present, and probable future, and concluded that the only safe base for 

 a paper currency issued by banks was a specie one. 



A vote of thanks was passed to Peter Cooper for his valuable commu- 

 nication. 



GOLD 



Being the regular subject of the evening, the Chairman called on Mr. 

 Stetson to open the discussion. 



Mr. Stetson. — I am not in the habit of discussing, but of bringing facts 

 before the meeting. Gold is too important in its bearings to be spoken of 

 without due preparation. I, therefore, prefer that some other gentleman 

 take np the subject, and I shall speak afterwards. 



The Chairman said, " gold as a measure of value is vastly important, but 

 as an article of commerce, and as a material to be used in the arts, it is of 

 far greater importance. This consideration then, should suggest the pro- 

 priety of taking up the sources whence gold is obtained as the theme of the 

 evening. In a good old book,, '• surely," says Job, " there is a vein for 

 the silver, and a place for gold where they find it." Seeing Dr. Draper 

 present, I will invite him to oblige us by giving us some of his reliable 

 knowledge. 



Dr. Draper. — I have not much experience of a practical kind, in gold 

 fields. I may, however, state that gold is gathered principally by amal- 

 gamation, and that it is always found in a state of more or less impurity. 

 I have not devoted much time to the mechanical part of the preparation or 

 obtaining of gold. 



Professor Hedrick had no practical experience in gold digging, but 

 thought that the matrix in which native gold is imbedded, disintegrates 

 in process of time, and so exposes the gold, which, may under such circum- 

 stances be best procured by washing. This was probably the plan employed 

 in the days of Job. When gold is found in veins, the rocks are pounded 

 into fine grit and gold is separated by amalgamation. In this case the 

 rocks from which it is obtained must be free from sulphur, or the mercury 

 will combine to some extent with the sulphur and be wasted. To get rid 

 of the sulphur the ores may be roasted, and so the sulphur be burned off, 

 or if the pulverized rock be left long enough exposed to the action of the 

 air the sulphur will be oxydized. Thus in old diggings which had been 

 abandoned for twenty years, the ores rejected as useless, had been so im- 

 proved by oxydation of their sulphur that on reworking, they were found 

 to be valuable. Nitre is occasionally used with ores of gold contaminated 

 with sulphur, for, being rich in oxygen, it will when exposed to heat, favor 

 the removal of all the sulphur. 



Prof. Renwick. — The general impression had been, that gold was only 



