CONTENTS. vil 
Number 299. 
Page 
Art. XXXVII.—Wave Length of the D, Helium Line; by 
oe Wael ae Se Moe dele eee te ell Lj, 857 
XXXVIIL—Additional Notes on Argon and Helium; by 
Hie Ambien eh 8 ee RR eS Sst a Le BOD 
XX XIX.—Recent Progress in Optics; by W. LeContE 
Peseta fe 3 ee RE SL ee OTT 
XL.—Effect of the Mutual Replacement of Manganese and 
Iron on the Optical Properties of Lithiophilite and T'r- 
piylite;s by 5.,L, Puneretp and) J: HW; Prarr 2.22... 387 
XLL—Ammonium- -Cuprous Double Halogen Salts; by H.. 
eavonmrs and Re. HURLBURT: 0 oso. LL 390 
XLII.—Some Phonolitic Rocks from Montana; by L. V. 
PTC RICO a ete ae ee ea pei ot kia: Sen 
XLIII.—Reduction of Selenic Acid by Hydrochloric Acid ; 
bys ree GOoeH and i. .S- EVvans; JR. 22.0422 52455% 400 
XLIV.—Reduction of Selenic Acid by Potassium Bromide 
in Acid Solution; by F. A. Goocu and W. 8. ScovitiE 402 
XLV.—Reptilia of the Baptanodon Beds; by O. C. Marsu 405 
XLVIL—Restoration. of Some European Dinosaurs, with 
Suggestions as to their Place among the Reptilia ; by 
ae. viarsn. (VW ith Plates V—VIE.)... 2... = Le. 407 
SCIENTIFIC INTELLIGENCE. 
Chemistry and Physics—Refractivity and viscosity of Argon and Helium, Lorp 
RAYLEIGH: Compound nature of the gas from Cleveite, U. Rune and F. 
PASCHEN, 413.—Specific refraction of Argon, 41€.—Color Photography, O. 
WIENER, 417.—Electric Aureole: and Stratifications in the Electric are and in 
discharges in rarified gases, LEHMANN: Magnetism of Asbestos, BLEEKRODE: 
Electric refraction of Liquids, P. DruDE: Double refraction of electric waves 
in ice, V. BIERNACKI, 418.—Double refraction of electric waves, P. LEBEDEW, 
419. 
Geology and Mineralogy—Temperature Variation of the Thermal Conductivity 
of Rocks, LoRD KELVIN and J. R. E. Murray, 419.—United States Geological 
Survey: 14th Annual Report for 1892-93, 423.—Gold fields of the Southern 
Appalachians, G. F. BECKER: Columnar sandstone, J. M. Curran: Petrology 
for Students, A. HARKER, 425.—Introduction to the study of Rocks, L. 
FLETCHER: Calaverite from Cripple Creek, Col., W. F. HILLEBRAND: Minerals 
from New South Wales, A. LiveRsIDGE, 426.—Contribution to the Mineralogy 
of Wisconsin, W. H. Hogpss: Tabellarische Uebersicht der einfachen Formen 
der 32 krystallographischen Symmetriegruppen, Dr. E. A. WULFING: Mineral 
Industry, its Statistics, Technology, and Trade in the United States and other 
countries to the end of 1894: Field Columbian Museum, Handbook and Cata- 
logue of the Meteorite Collection, O. C. Farrineron, 427. 
Botany--Synoptical Flora of North America, vol. I, A. Gray, S. Watson, B. L. 
ROBINSON, 428.—Another example of Chalazogamy, Dr. 8S. NAWASCHIN, 429. 
Miscellaneous Scientific Intelligence—Meeting of the British Association, 429.— 
Origin of Thunderstorms, 430.—Uniformity of size of pages of Scientific Socie- 
ties Publications: Map of the wooded area of Connecticut: Principles and 
Practice of Agricultural Analysis, H. W. Witey, 431. 
Obituary—Professor CHARLES V. RILEY, 432.—M. Louis PASTEUR: Professor 
ELI WHITNEY BLAKE: Dr. ALBERT K. Foote, 434. 
