378 Clarke and Schneider — Experiments upon the 



Art. XLVI. — Experiments upon the Constitution of certain 

 Micas and Chlorites ; by F. W. Clarke and E. A. 

 Schneider. 



Shortly after the publication of our first joint paper upon 

 the constitution of the natural silicates,"- we received from Mr. 

 A. Losch, curator of minerals in the Imperial School of Mines 

 at St. Petersburg, some highly in^ortant material bearing upon 

 our researches. Our work upon leuchtenbergite, it will be 

 remembered, was defective, on account of impurity in the 

 specimens at our disposal ; and Mr. Losch therefore sent us a 

 supply of the perfectly pure mineral, selected with extreme 

 care, and in the very best condition for. study. To this gift he 

 added four other minerals which he thought would be of 

 interest to us, and upon these five specimens our present com- 

 munication is founded. 



The minerals, and the analyses are as follows : 



A. Xanthopbyllite, var. Waluewite, from the Nikolai-Maxi- 

 milian mine, District of Slatonst, Ural. 



B. Clinochlore from the same locality. Green, broadly 

 foliated, closely resembling the mineral from West Chester, 

 Pennsylvania. 



C. Lenchtenber^ite from Slatonst. 







D. "Dialla 



ge serpentine " fr 



om the R: 



iver Pold 



newaja, 



trict of 



Syssert, 



Ural. 









E. White : 



mica from Miask, 



Ural. 









A. 



B. 



C. 



D. 



E. 



SiO„ 



16-85 



30-84 



30-00 



42-55 



44-17 



TiO"„ 



trace 



















A1A 



42-33 



18-31 



20-43 



1*25 



37-35 



Fe„0 3 



2-35 



1-94 



1-68 



1-56 



1-29 



FeO 



0-20 



1-08 



0-14 



' 1-52 



0-20 



MnO 



















o-io 



CaO 



13-30 





0-21 



none 







MgO 



20-77 



34-38 



34-26 



40-05 







KoO 

















10-00 



Na 2 















1-14 



Chromite 















0-37 







F 



















0-90 



H„0, 105° 



0-04 



0-55 



0-55 



0-21 



1-06 



"~250°-300° 0-12 



0-49 



0-35 



o-ii 



0-53 



" ignition 



4-44 



12-84 



12-85 



12-15 



4-14 





100-40 



100-43 



100-47 



99-77 



100-88 



Less = F 

















•37 



100-51 

 *This Journal, Oct., Nov., and Dec. 1890. 



