54 REPORT — 18S9. 



vitreous, semi-transparent, well crystallized. The composition was, 



Silica 37-90 containing 19'688 oxygen. 



Alumina 18-15 8-4751 



Protox.iron 4-89 1-112-j > 20-578. 



Lime 34-69 ^'^"^^ > 19-103 i 



Mairatst} 3-23 l-^^i " 



98-86 

 5. Specimen of Egerane from Eger in Bohemia. 

 Its characters agreed with those of the other specimens, with the 

 exception of its colour which was cinnamon-brown, and its opacity. 

 The result of the analysis was, 



Silica 38-40 containing 18-819 oxygen. 



Alumina 18-15 8-4751 



Protox.iron 7-40 1-684"] V 20-620. 



Prot. manganese I 12-14 J 



Lime 33-09 9-293 7^^^^^ 



Magnesia 3-02 1*168 J 



100-06 

 The inference from the whole of these analyses is, that the composi- 

 tion of idocrase may be represented by the formula before given, viz. 



7 (FO CaO MgO M0)3 SiOg + 5 Al^ O3 SiOj, 

 which may also be referred back to the fundamental formula of the 

 garnet, 3 RO SiOg + R2O35 SiOg. This conclusion suggests the idea, 

 that by attending more minutely to the exact representation of the 

 analytical results in the formula, new light might possibly be thrown 

 upon some points in the doctrine of Isomorphism. 



Some observations on Meteoric Iron found in different parts of the 

 United States of America. By Charles Upham Shepard, M.D., 

 Professor of Chemistry in the Medical College of the State of South 

 Carolina, and Lecturer on Natural History in Yale College, Con- 

 necticut. 



During the last winter Dr. Hardy of Ashville, North Carolina, pre- 

 sented to the author a mass of apparently native iron, weighing seven 

 or eight ounces, that had been detached from a ball of about five inches 

 in diameter, which was found loose in the soil about five miles west of 

 Ashville, in Buncombe county. North Carolina. The specimen evinced 

 a decidedly crystalline structure, and even approached, in general figure, 

 that of a flattened octohedron. Its surface had a dissected or pitted 

 appeai-ance, occasioned by the removal of portions of the external 

 laminae during its separation from the original mass. The cells and 

 cavities thus apparent were perfectly geometrical in shape, being either 



