CONTENTS. yii 



Astronomy.— Elements of Borelly's Comet, A. N. Skinner, 323.— Photographic 

 Spectra of Stars. W. Hugoixs. 324.— Satellites of Jupiter, D. P. Todd, 325. 



Meteorology of i :nMi>ii.('.,|.,i-ailo: American Mi,-i, .-,-.,, ,i,- :l I Su.-ietv: Structure of 

 Precious Opal: Shoal in the Atlantic, 32ii. — (}l„t„„nj.—\Y,,if^,u^ Sail..rius v,.n 



NUMBER LXXVII. 

 Art. XXXVII.— On Vortex Rings in Liquids; by J. Tuuw- ''"*"• 



XXXVIII.— An account of the l3is«-o"vi-riVs"i"n Yennont Ecol- 

 ogy of the Rev. ArcusTus Win.;; 1»v .Tamks I). Dan v :i:i" 



XXXI X. -Notes on the History of //- Ih'mtl,,,* t„h, ,•„,<„.*, the 

 so-called Jerusalem Artichoke ; bv J. IIammum, Tiu.m- 

 bull and Asa Gray, " ,UV 



XL.— A new Investigation of one ..ft he haw-,,! Fri.-ti.m ; by 



A. S. Kimball, _ _ ... 353 



XLL— Examination of American Columbic Aci.l Minerals; 



by J. Lawrence Smith, . .359 



XLIL— On the Sensitiveness to Light of various Salts of Sil- 

 ver ; by M. Carey Lea, 369 



SCIENTIFIC INTELLIGENCE. 



■ •"■•: - 

 LOT, 372.— Equivalence of Nitr.-en. VirmE Miivkr: A new ,,. ■: 



»nube, 1. Belt. 383. — ' 



Samarskite of X > faise. :)!((). 



Publications i Amy, Dun Echt (Aberdeen), 



398.— La Luce Zodiacale, sue Leggi e Teoria Cosmico-Atmospherica, dedotte dalle 

 Osservazione di ill, 399.— Observat ■ Comets 18176. 



Ic School, 41 



- 



i and Summer 

 Irvington, Indiana: Report of 'the Chief of Engineers to the Secretary of .A 



.latest Investigati- 

 on Flammarion's B 





