358 Scientific Intelligence. 



Bulletin No. •!. Iron Ore Deposits of the Bristol Mine, Pon- 

 tiac County, Que. JMagnetometric Survey, etc. ; by E. Linde- 

 MAN. Miignetic Concentration of Ores ; by Gko. C. Mackknzik. 

 Pp. 15, Avith 2 plates and 2 figures. 



Bulletin No. 3. Recent Advances in the construction of Elec- 

 tric Furnaces for the production of Pig Iron, Steel, and Zinc ; by 

 EuGENK Haanel. Pp. 76, with one plate and 17 figures. No. 68, 



Report of Analyses of Ores, Non-Metallic Minerals, Fuels, etc. 

 made in the Chemical Laboratories during the years 1006, 1907, 

 1908, arranged by F. G. Wait. Pp. 1'26 with 2 plates. No. 59. 



Map of the Porcupine Gold Area, districts of Sudbury and 

 Nipissing, Ontario; by A. G. Burrows, geologist, and W. R. 

 Rogers, topographer. 



9. Barbierite, a Monoclinic Soda Feldspar ; by Waldemar 

 T. Schallkr. (Communicated.) — The existence of a monoclinic 

 dimorphous form of albite, isomorphous with orthoclase, lias 

 long been suggested, but the presence of soda in orthoclase analy- 

 ses has generally been otherwise explained. In such cases the 

 presence of albite or anorthoclase has generally been suggested 

 as the explanation of the soda present. In a I'ecent paper by 

 Barbier and Prost,* analyses are given of feldspars in which the 

 cleavage angle varies but a few minutes from 90° and in which 

 soda is present in molecularly greater amount than the potash. 

 The maximum soda content is reached in a feldspar from Kragero, 

 Norway, in which only 1-15 per cent K^O was found. 



Examination under the microscope showed that (with one 

 exception) albite was not present, and the existence of a mono- 

 clinic soda feldspar isomorphous with orthoclase must be admit- 

 ted. 1 propose to call this particular monoclinic soda feldspar 

 harbierite, in honor of Prof. Ph. Barbier, of the University of 

 Lyons, Fi'ance, who has recently published, in addition to the 

 paper above cited, another one on the feldspar group, in which 

 he gives a definite chemical diflPerence between orthoclase and 

 microcline.f Further analyses of soda-rich orthoclases are given 

 by him in a later paper. J The feldspar from Kragero is nearly 

 pure barbierite. 



In a very recent number of the Neues Jahrbuch filr Mineralo- 

 gie, etc., Angel gives a description of a soda-bearing monoclinic 

 sanidine,§ which contains 4-92 percent Na^O and 6'73 K^O. The 

 cleavage angle (001) : (010) is 90° 01' and the extinction on (001) 

 is parallel. The feldspar is monoclinic and consists approxi- 

 mately of equal parts of the isomorphous orthoclase and barbier- 

 ite. In this paper are given several references to earlier ones on 



* Barbier, and Prost, A., Sur I'existence d'un feldspath sodique mono- 

 clinique, isomorphe de I'orthose, Bull. Soc. Chim., Ill, p. 894, 1908. 



f Barbier, Ph., Recherches sur la composition chimique des feldspaths 

 potassiques, Bull. Soc. Franc, mineral., vol. xxxi, p. 152, 1908. 



X Barbier, Ph. and Gonnard, F., Analyses de quelques feldspaths francais. 

 Bull. Soc. Franc, mineral., vol. xxxiii, p. 81. 



§ Angel, Franz, tJber einen Natronsanidin von Mitrowitza, Nenes Jahrb. 

 Mineral. Gaol. u. Pal., Beilage-Band, xxx, 254, 1910. 



