Vili CONTENTS. 
Astronomy.—Spectrum of the Aurora, E. S. HOLDEN, 423. 
. Scientific Intelligence.—Institute of Technology, Boston: Annual Re- 
of the Director of the Meteorological Observatory, Central Park, New York: 
Hayden's Geological Exploration in = Rocky Mountains, 424.— Obituary.-— 
Rev. John P. acatin John F. Frazer, 
NUMBER XXIV. 
P 
Arr. XLIX.—On a simple and precise method of measuring 
the wave-lengths and velocities of sound in Gases; and 
on an rid tesoest ud the me poses in the oe of an 
Acoustic Pyrometer; by ALFRED M. Mayer,..---.-.-- 425 
L.—On ‘le stability of the Collodion Film ; oy Lewis M. 
NES Siete ee SariSaiens is een ad ac gh eee 430 
LL—Note ar cient Orthoclase, found at the O den 
ae separte Township, Sussex Co., N.w.; by. Prof. 
ee ee ee Ce ates GS es rel Se ak 33 
LIL. =n Soil Analyses and their Utility; by Eve. W. H1- 
ee wee Se ee ee ee ae eg 434 
LIL_Tke Heat produced in the ‘Sele =e the effects of 
Exposure to Gold; by Jom) Dearen,. 222. 2 ek 445 
LIV.—On the rtzite, Lucastane iat acasind rocks ‘of 
the vicinity of Great Barri rrington, Berkshire Co., Mass. ; 
hee U. Wawa AO0gtInGged),. . os oko ose cc 450 
LV.—On the relation between Color and Geographical Distri- 
bution in Birds, as exhibited i n Melanism and Hyper- 
chromism ; by Risser Bibewax.. 0 454 
LVL—A Theory of the Ce of the great Features of 
the Earth’s Surface; by Josepu LeConre (conclude oe . 460 
VIL—On a crystal of Sadat. from Delaware Co. ; 
by Epwarp 8. Dana,. OG oS ENE ee 3 
LVIII.—Spectrum of Lightning s by Epwarp 8. Ho ys 474 
Letter from Dr. B. A, Gourn, irector of the Ohasrvaicey at 
Cordoba 
SCIENTIFIC INTELLIGENCE. 
etric Flames, by R. Konic, 481.—On i 
“ight enited oy the et ee compounds of uranium, BECQUEREL, 486. 
of the Aurora Borealis , VoGEL, 487.—On the heat of expan 
Sat 2 solid tation Burr, 488. 
met and Natural History.—Wyo oti Coal Formations, E. Bs Cope: Decaisne’s 
i grt of a Gens Pyrte @ —Botanical suppleme: to the fifth Annual 
U, 8. Geological Saevay of the Territories fot ‘Tet, by M. Lzs- 
si ahs ion 
Astronomy.—Elements of Alceste, by C. H. F. Prrers, 495. 
Miscellaneous Scientific Intelligence.—Analysis of the Meteoric Iron of Los Angeles, 
California, by C. T. Jackson, 495.—Tables and Diagrams relating to non- 
_ condensing Engines and a by W. P. TRowpRripGE: Chemistry, Inorganic 
and age with ee ae A BLoxaM, 496. Pies of the Mt. Uniache, 
Oldham. Renfre Y Gold Mining Districts H. Young Huinp, 497.— 
orumndin al Engravings by the Observatory of Cierverd College, 4 497,.— Obituary. 
—John F. 
