Review of Dana's Mineralogy. 



377 



thorities and foreign languages for the purpose in question, can 

 fully appreciate the thankless nature of the labor. The number 

 of species retained is about four hundred and eighty. By care- 

 ful comparison of analyses, and by researches undertaken ex- 

 pressly for the work, some of the dark points of American min- 

 eralogy have been cleared up, and many species turned over to 

 our table of synonyms on a following page. 



This part of the work is well illustrated by figures, about sev- 

 enty of which are new in this edition. The author has added 

 many original figures of American species. We have space only 

 to extract a few notices where the matter is new, and particu- 

 larly interesting to American readers. We follow the order of 

 the treatise. 



" Borate of Lime. Borocalcius obliquus. 

 (Jl. A. Hayes, private communication to the author.) 



" Primary form, an obtuse oblique rhombic prism ; 

 M : M=9T 30' and 82° 30'— 82° 36', (Teschema- 

 cher.) Secondary form, the annexed figure ; M : e 

 = 147° 30', (Teschemacher.) Also in masses having 

 a globular form,- consisting of interwoven fibres. 



" Crystals colorless and transparent. Fibrous masses 

 opaque, snow-white, silky, and have a peculiar odor. 



" Composition, according to Mr. A. A. Hayes, a 

 Hydrous borate of lime ; the exact constitution has not 

 yet been determined. In warm water the fibrous 

 masses expand and form a consistent paste with more 

 than eight times their volume. Mr. Hayes states that 

 this variety contains more water than the crystals. 



" Obs. This salt occurs quite abundantly on the dry plains near 

 Iquique, S. A., associated with magnesian alum, (Pickeringite of Hayes,) 

 where it was obtained by Mr. J. H. Blake. The crystals are some- 

 times a quarter of an inch long." (p. 243.) 



u Chlorophyllite. Stylus foliaceus. 



(" Esmarkite, Erdmann, Jahresb. 1841, p. 174. Chlorophyllite, 

 Jackson, 1st An. Geol. Rep. of New Hampshire, p. 152. Pinite.) 



" Occurs in six and twelve-sided prisms. Highly foliated parallel 

 to the base of the prism ; sometimes also a prismatic cleavage more or 

 less distinct. 



" H. of basal plane 1*5 — 2 ; the lateral edges will scratch apatite. 

 G.=2 - 705, Jackson ; 2*709, Erdmann. Lustre of basal plane, pearly ; 



Vol. xlvi, No. 2.— Jan.-March, 1844. 48 





