AMERICAN INSTITUTE. 685 



quantity. Why not try first to regulate one of them — silex or 

 alumina, for instance — determine one forever by a suitable pro- 

 cess, then another, and so on. Chemical and mechanical tests 

 can be made to show when the element silex is right. When 

 that is decided positively, try other impurities. In chemical 

 analysis we are obliged to separate one element first, and so on. 



Next meeting, subject, " Photography." 



The Club adjourned. 



H. MEIGS, Secretary. 



March 24, 1858. 



Present— Messrs. T. B. Stillman, R. L. Pell, Tillman, Haskell, 

 Judge Livingston, Stetson, Prof. Nash, Seeley, Johnson, Dixon, of 

 Jersey City, Timpson, Geissenhainer, Cohen, and others — twenty- 

 eight members in all. 



Thomas B. Stillman, late of the Novelty Works, in the Chair. 



Henry Meigs, Secretary. 



The Secretary read his translation of the letter from Baron Von 

 Humboldt, thanking the Institute for the present of volumes of 

 our Annual Transactions. Dated Berlin, Feb. 25th, 1858. 



The subject of Photography being called up, Mr. Pell remarked, 

 That Photography, or Heliography, is an art, by which we are ena- 

 bled, through the medium of light, to obtain not only accurate, 

 but splendid representations of objects. So early as 1803 It was 

 known that nitrate of silver would become dark under the sun's 

 rays, but no mode could be discovered at that period, either by 

 Wedgewood or Sir Humphrey Davy, to fix the pictures after they 

 were obtained. Consequently they abandoned the experiments. 



In 1827 or '28, pictures were exhibited at the rooms of the 

 Royal Society in London, on glass, produced by light, the work 

 of a Frenchman by the name of Niepce, who afterwards went 

 into partnership with the celebrated Daguerre, and I suppose was 

 entitled to a portion of the honor, which was never awarded to 

 him, of discovering the process of silvered plates. 



