336 Miscellaneous Intelligence. 



The formula deduced is K„0, 12(Fe,Mg)0, A1„0 3 13Si0 3 + 5H„0. 

 — G. Nordenskiold in Geol Mr. Fork., xii, 348, 1890. 



Kaliborite. — A hydrous borate of magnesium and potassium 

 occurring with pinnoite, which it closely resembles, near Aschers- 

 leben, Prussia. It is massive with granular structure, and spe- 

 cific gravity=2 - 05. An analysis gave: 



B 2 3 57-46 MgO 12-06 K 2 6"48 H 2 24-00 = 100 



— W. Feit in Chem. Zeitung, 1888, 1889. 



Phosphosiderite. — A hydrous ferric phosphate described by 

 W. Bruhns and K. Busz as occurring at the Kalterborn mine 

 near Eiserfeld. It is orthorhombic and appears in prismatic crys- 

 tals, tabular parallel to the brachy-pinacoid. Hardness=3 , '75, 

 specific gravity = 2 # 76. Color peach-blosson red or reddish violet. 

 An analysis gave : 



P 2 5 38-85 Fe 2 3 44-30 H 2 17-26 = 100-41 



This corresponds to 4(FeP0 4 ) + VII„0, which brings it very near 

 strengite, to which it is also allied in form, though the two 

 minerals appear to be distinct. — Zeitschr. JTryst., xvii, 555. 



Sigterite. — Described by Rammelsberg as a new member 

 of the feldspar group. It occurs associated with the eudialyte 

 and albite of Sigtero, Norway. Structure granular; color gray; 

 cleavage like that of ortboclase, with polysynthetic twinning. 

 Extinction on (001) inclined ± 3|° to 4^°, and on (010) + 16° to 

 their intersection-edge. Specific gravity 2-600 — 2-6222. An 

 analysis gave : 



Si0 2 50-16, A1 2 3 28-64, Na 2 13-63, K 2 3-96, FeO 1-97, CaO 0-98, MgO 0-16 



ign. 42 — 99-92. 



Deducting a little admixed augite, this becomes 



Si0 2 50-54, AI0O3, 30-64, Na 2 14-58, K 2 4-24 = 100, 



which gives the formula (Na ] K)„Al„Si 3 O 10 , or that of an anhydrous 

 natrolite. — Jahrb. Min., ii, 71, 1890. 



Akermanite. — A lime-magnesia silicate, containing no alu- 

 mina, and belonging to the tetragonal system like melilite, 

 with which it is closely related. It is not known in nature but 

 has been obtained by Vogt in connection with an important 

 series of experiments upon the formation of minerals from fusion. 

 — Arch. Math. Nat. Uristiania, xiii, 311, 1890. 



III. Miscellaneous Scientific Intelligence. 



1. American Association for the Advancement of Science. — 

 The thirty-ninth meeting of the Association opened at Indian- 

 apolis on Tuesday, August 1 9th, nineteen years after the previous 

 meeting at this place, Professor George L. Goodale, of Cam- 

 bridge, President. The address of the retiring president, Prof. 

 Mendenhall, discussed in a forcible way some of the relations of 

 science to the general public. 



