J. E. Whitfield — The Rochwood Meteorite. 



387 



certain other chlorides, will undoubtedly in the future be of great 

 value in aiding toward a solution of the problem of rendering 

 permanent photographic images in natural colors. Indeed, it 

 was Poitevin, I think, who found that his colored images resisted 

 light better when treated with lead chloride and dextrine. The 

 property was observed, but the nature of the action remained 

 obscure. We now see its explanation in the tendency of the lead 

 salt to check reduction. Zinc chloride I found available like 

 lead chloride, to regenerate white silver chloride by the action 

 of light on colored photochloride, and thus to give aid toward 

 that very difficult requirement in heliochromy, that white light 

 shall express itself by producing white. 

 Philadelphia, September 24, 1887. 



Art. XLTII. — The Rochwood Meteorite; by J. Edward 

 Whitfield. 



The Rockwood meteorite was found about the middle of 

 March, 1887, by Mr. Elihu Humbree on the range of the Crab 

 Orchard Mountains. The field in which it was picked up is 

 now owned by Mr. W. B. Lenoir, and is situated 8-J miles west 

 from Rockwood, Tenn., in Cumberland County. The material 

 for analysis was received from Messrs. Ward and Howell, of 

 Rochester, N". Y., the present owners of the meteorite, to whom 

 we are indebted for the privilege of description. 



g Natural size. (The main mass.) 



There were three pieces found, the smallest measuring 

 4x3x2|- inches and weighing 3 pounds 10£ oz. ; the next 

 larger measuring 7£x6^x2f inches and weighing 5 pounds 13£ 

 oz. ; and the largest, an irregular egg-shaped mass a little flat- 

 tened on one side, measuring 14f X 10 x8£ inches, with a weight 



