and Shepard's Treatise on Mineralogy. ' 343 



Esmarkite, (p. 176.) This mineral, described by Erdmann, 

 is identical with Dr. Jackson's Chlorophyllite, (see p. 62,) which 

 differs in composition from Bonsdorffite, (or Hydrous Iolite,) and 

 Fahlunite, only in containing less water. 



Nuttallite, (p. 220.) Nuttallite has been considered a distinct 

 species on the ground of Thomson's analysis. But its crys- 

 tallization is the same with scapolite, and, until examined by 

 another chemist, it should not rank as a species. In Mr. Alger's 

 work it occupies a distinct place, some fifteen pages in advance 

 of scapolite, from which it is separated by elaeolite, Hauyne, hy- 

 drous anthophyllite, periclin, Labradorite, albite, analcime, soda- 

 lite, &c. 



Elaolite, (p. 221.) Elaeolite, which is here continued as a 

 species, Scheerer has shown to be identical with nepheline, both 

 in composition and structure.* 



Calstronbaryte, (p. 306,) Emmonsite, (p. 309.) These are 

 admitted mechanical mixtures, and might better be rejected than 

 retained with a query. 



Gbthite, (p. 355.) Distinct from Limonite, with which it is 

 united, in containing less water. The formula of Limonite 



'*■ 



(Brown Iron Ore,) is Fe 2 K 3 , while that of Gothite is 



Titaniate of Iron (Menaccanite,) Crichtonite, Ilmenite, (pp. 

 378 — 380.) These minerals are admitted as distinct species. 

 The compounds of titanic acid and iron are so various, that many 

 more might be added ; and as they are all isomorphous, it ap- 

 pears preferable to unite them under one species, making the dif- 

 ferent compounds varieties. The analysis given of Hystatite, (p. 

 3 ?9,) is that of Menaccanite, according to Von Kobell, the au- 

 thor quoted. Von Kobell gives Mosander's analysis of Hystatite 

 as follows : Titanic acid, 24-19; protoxyd of iron, 1991 ; per- 

 °xyd of iron, 53-01 ; lime and magnesia, 1-01 ; silica, M7.f The 

 Washingtonite of Shepard (p. 603) is identical nearly with the 

 variety Hystatite. 



Torrelite of Thomson, (p. 384.) The Torrelite from Middle- 

 town is the common columbite of that place. In crystallization 

 11 is identical with the Bodenmais columbite. Mr. Alger has not 

 distinguished the kimito-tantaiite (Ferro-tantalite) from the co- 



* PoggendorPs Annalen, xlix, p. 359, 1340. 



t Grundztlge der Mineraiogie, p. 318, Nttmberg, 1838 



