58 JOURNAL OF THE [April, 



by the deflections of the plate. Of great interest is the fact that 

 these thin plates of quartz, when punctured by a pin or needle- 

 point, separate with rhombohedral cleavages, showing that 

 quartz, the cleavage of which is otherwise never very facile, when 

 prepared in these sections is one of the most highly cleavable of 

 all minerals. 



" To increase the sensibility of the tourmaline forceps, Werlein 

 has attached to one of the tourmalines a small condenser of didy- 

 mium glass, producing excellent results. 



" Dreh-Apparat — turning apparatus — devised by Prof. C. 

 Klein, of Berlin, and made by Fuess, of Berlin. Described in 

 Sitzimgsberichte der Koniglich Preussischen Akademie der Wissen- 

 schaften zu Berlin, Sitzung der physikalische-mathematischen 

 Classe vom 30. April. ' Krystallographisch-optische Untersuch- 

 ungen. Ueber Construction und Verwendungvon Drehapparaten 

 zur optischen Untersuchung von Krystallen in Medien ahnlicher 

 Brechbarkeit,' von Carl Klein, pages i to 10. Used to examine 

 entire crystals, fragments, and minerals cut into gem form, under 

 the polariscope and microscope. 



" Axis-measuring apparatus on the Adam principle, made by 

 Fuess, of Berlin, Germany, for examining the optical properties 

 of minute scales of fragments of minerals. Described in Ueber 

 Mikroskope fiir Krystallographische und Petrographische Unter- 

 suchungen, von R. Fuess, Berlin, S. W., 108 Alte Jacob Strasse, 

 pages 25 to 28, 1891. 



" In connection with these two pieces of apparatus, I would 

 remark that Pulfrich gives a list of twenty-six liquids of varying 

 refractive indices, 1.5381 dispersion equalling 0.0142 to iodide of 

 mercury dissolved in aniline and chinoline refractive indices 2.2, 

 and when dissolved with lepodine a still higher index. 



" Pocket lens, one-fourth inch, made of oligoclase feldspar 

 from Bakersville, North Carolina, described by George F. Kunz 

 in Amer. Jour, of Sci., series iii., vol. xxxvi., page 222. 



" Artificial Ruby, made by E. Fremy. Two series of slides of 

 detached crystals, and one piece of crucible with rubies adhering. 

 Described by E. Fremy in 'Synthesis of the Ruby,* Paris, 1891, 

 page 58, plate 21, published by Vve. Ch. Dunod. 



"After listening to Dr. Julien's paper, I would state that I 

 visited the localities last summer, and conform with the observa- 



