838 General Notes. [October, 



the same reason aluminium foil is stated to be better fitted than 

 platinum foil for the fusion of alkaline carbonates, the detection 

 of manganese, etc. 



Ersbyite.— This feldspar, hitherto regarded as an anomalous 

 variety of doubtful existence, has recently been shown by F. J. 

 Wnk, to be a potash microcline. The large percentage of lime 

 given in former analyses is proved to be due to an admixture of 

 calcite. After purification in weak acid, the following composi- 



Si0 2 AI 2 3 CaO K 2 Na,0 



66.18 I9 . 52 .36 13.03 . 9 i 



The feldspar occurs in colorless crystals at Pargas, Finland, and 



is intimately associated with another feldspar, now shown to be 



andesite. The optical properties are identical with microcline, 



and the name ersbyite must be dropped from the list of speci/es. 



Mineralogical Notes.— N. H. Darton is giving, in the Scien- 

 tific American Supplement, a popular account of the mineral local- 

 ities and the minerals to be found in and around New York city. 

 The articles are written in a familiar style, and will be of great 

 assistance to beginners in mineralogy living near New York city. 

 Professional mineralogists also will be glad to know the exact 

 localities of the specimens in their cabinets, and will be interested 



in the full description of their method of occurrence. The 



Proceedings of the Mineralogical and Geological Section of the 

 Academy of Natural Sciences of Philadelphia are offered for sale 



at fifteen cents. Crystallographers will be interested in the 



abnormal diammd crystals recent! v described and figured by 

 Purgold of Dresden. One of these has eight projecting triangu- 

 lar points— the result of repeated twinning. The second part 



of Professor Tschermak's " Lehrbuch der Mineralogie " (Vienna) 

 has recently been issued. It is a valuable work, embodying the 

 latest results of mineralogical research. Selenium and tellu- 

 rium have been found in the sulphur of Japan. 



GEOGRAPHY AND TRAVELS. 1 

 The Rescue of the Crew of the Eira— The steam whaler 

 Hope, Captain Sir Allen- Young, which sailed from the Scotch 

 port of Peterhead about June 20th, to search for and relieve the 

 crew of the Rim, has been most successful in its mission, having 

 returned with all the members of the missing expedition on 

 board. The Bra left Peterhead on the 14th of June, 1881. The 

 ice that season reached very far south, and no opening could be 

 found f enable her to get north until the middle of July. Franz- 

 Josef's Land was reached on July 23, and the Eira steamed along 

 the coast to within fifteen miles of Cape Ludlow. The ice was 

 closely packed to the north, so it was decided to return to Gray 

 1 Edited by Ellis H. Yarnall, Philadelphia. 



