and Laboratory Methods. 1393 



NOTES ON RECENT MINERALOGICAL 

 LITERATURE. 



Alfred J. Moses and Lea McI. Luquer. 



Books and reprints for review should be sent to Alfred J. Moses, Columbia University, 



New York. N. Y. 



Clark, F. W., and Steiger, G. The Action of The data given yield further proof of the 



Ammonium Chloride upon Natrolite, Scole- availability of the method for investiga- 



cite, Prehnite, and Pectolite. Am. Jour. . ■ ^ ^, i • i ,-^ ^- r 



Sci iv 9: ^41; igoo. ^^°" ^"^° ^"^ chemical constitution of 



silicates. 

 Natrolite and Scokcite proved to have no constitutional water, but similar 

 chemical formulae, which, however, are not those of ortho-silicates : 

 Natrolite, NasAUSigO^o .2H2O. 

 Scolecite, Ca A^Si^Oio -SHjO. 

 Prehnite may be regarded as having constitutional water and ortho-silicate 

 formula. 



Pectolite differs widely from these other minerals as regards the ammonium 

 chloride reaction ; but experiments suggest the probable existence of a hydrous 

 ammonium pectolite. l. Mci.l. 



Clark, F. W. and Steiger, 0. The Action of Authors show that both analcite and 

 Ammonium Chloride upon Analcite and , ., , , ^ j ^ ocao -^i ..i • 



Leucite. Am. Jour. Sci. iv, 9: 117, 19C0. leucite, when heated to 350° with this 



reagent in a sealed tube, yielded the 

 same definite compound, ammonium leucite NH^Al SioOy. This reaction was 

 fairly general in character, and analagous results were obtained with other 

 species. 



By substituting in many minerals a volatile base for fixed bases, silicates are 

 obtained which split upon ignition in such a way as to shed light upon their 

 molecular constitution. 



The conclusion was reached that analcite and leucite were not true meta- 

 silicates, but pseudo mixtures. l. Mci. l. 



Parsons, Charles L. The Use of Metalhc Sod- Contrary to the statement of Hempel, 

 ium in Blowpipe Analysis. Jour. Am. Chem. i c ^ j i.u r j- 



Soc.23: 159, Mar. 1901. ^^o first proposed the use of sodium 



in blowpipe analysis, the author finds 

 that the reduction of metallic compounds by means of sodium takes place with 

 the greatest ease on charcoal. The following procedure is recommended : A 

 piece of metallic sodium 3 or 4 mm. in diameter is hammered flat. The powdered 

 substance to be tested is spread upon and pressed into the metal, and the whole 

 turned into a little ball. It is placed in a slight depression of a piece of char- 

 ■ coal, and ignited with a match or Bunsen flame. The residue is heated before 

 the blowpipe, and fusible metallic particles readily collect into a globule ; at the 

 same time coatings of the volatile metals are obtained. Treated in this way, 

 garnierite gives magnetic nickel, chrysocolla a copper button, and cassiterite a tin 



