484 Scientific Intelligence. 



provided with small replica transmission gratings. The rela- 

 tively great length and thinness of the flame obviates the neces- 

 sity for a spectroscope slit." — Phil. Mag., xxxiv, 243, October, 

 1917. H. s. u. 



9. X-Ray Band Spectra. — An outline of two papers by de 

 Broglie on this subject was given in the June, 1917, number 

 of this Journal. Essentially the same text has since appeared 

 in another French journal {vide infra) with, the addition of 

 three excellent half-tone plates. The present notice is intended 

 to call attention to the scientifically beautiful reproductions of 

 the spectrograms of the absorption spectra produced when the 

 X-rays from a tungsten target were allowed to fall upon metallic 

 screens each of about 0.01 mm thickness. The first figure shows 

 the lines of the K and L series of tungsten together with the 

 dark bands due to the bromine and silver in the photographic 

 emulsion. The remaining figures pertain to the absorption 

 bands (light regions) of molybdenum, cadmium, antimony, 

 barium, tellurium, iodine, mercury, gold, lead, uranium, and 

 thorium. The wave-lengths of the edges of the bands of iodine 

 and tellurium conform to the atomic numbers and chemical 

 sequence of these elements and not to their supposedly anomalous 

 atomic weights. — Journal de Phys., v, 161, May-June, 1916. 



H. s. u. 



II. Mineralogy and Geology. 



1. Xew Mineral Names ; by W. E. Ford (communicated — con- 

 tinued from vol. xliii, pp. 493-494, June, 1917) : — 



CatOptrite. Katoptrite. Gustav Flink, Geol. For. Forh., 

 xxxix, 431, 1917.— Monoclinic. a : ^; : c = 0-79223 : 1 : 0-48985 ; 

 ^ = 78° 57'. Observed forms : a (100), ^(010), c(OOl), m (110), 

 /(210), n(120), t?(012), e(032\ o (212), ^9 (232), ^(272), r(212). 

 Angles ; m : a = 37° h'l\ (^ : ^ =: 67° 29', c : a = 78° 57'. Crystals 

 commonly minute and tabular parallel to b (010). Cleavage 

 parallel to e (OOl) very perfect. H. — 5*5. G. = 4-5. Color is 

 black with metallic appearance. In thin splinters, red. Ax. pi. 

 parallel to h (010). Bx^e makes 14-15° with trace of cleavage. 

 Axial angle small. Inclined disi>ersion p > v. Strongly pleo- 

 chroic, red-brown to red-vellow. Optically +. Comp. — 2810^. 

 Sb.p^.2(Al,Fe)^03.14(Mn,Fe)0. Anal, by Mauzelius, SiO, 7-75, 

 Sb,0^ 20-76, A1^03 9-50, Fe.p, 3-58, FeO 2-44, MnO 52-61, MgO 

 3-06, CaO 0-58, H/) O'll, Total 100 39. Found embedded in 

 calcite with magnetite and other minerals in the Brattsfor mine 

 at Nordmarken, Sweden. Name derived from Karoimov, a mirror., 

 in allusion to its brilliant cleavage surfaces. 



Ectropite. Ektrojnte. Gustav Flink. Geol. For. Forh., xxxix, 

 426, 1917. — Probably monoclinic. In thin crystals, tabular parallel 



