CONTENTS OF N° ^A^^.— Fourth Series, 



XXIX. On the Cooling of Gases. By MM. Jamin and Ri- 

 chard page 241 



XXX. On an Improved form of Filter-Pump. By T. E. Thorpe, 

 F.R.S.E. (With a Plate.) 249 



XXXI. On the Specific Heat of Carbon. By H. F. Weber, Assist- 



ant in the Physical Laboratory of Geh.-R. Helmholtz 251 



XXXII. On a precise Method jjf tracing the Progress and of deter- 

 mining the Boundary of a Wave of CJonducted Heat. By Alfred M. 

 Mayer, Ph.D., Professor of Physics in th>s Stevens Institute of Tech- 

 nology, Hoboken, N. J., U.S. America T 257 



XXXni. On Electrolysis, and the Passage of Electricity through 

 Liquids. By G. Quincke » w . . - ,. . -, 261 



XXXIV. Notice respecting some new Facte i^he early History of 

 Logarithmic Tables. By J. W. L. Glaisher, B.A.,- F.R.A.S=, Fellow 



of Trinity College, Cambridge !,. • ^* " *^ 291 



XXXV. On the Definition of Intensity in the Theories of Light 

 and Sound. By Robert Moon, M.A., Honorary Fellow of Queen's 

 College, Cambridge 304 



XXXVI. On the Chemical EfiSciency of Sunlight. By James 

 Dewar, Esq 307 



XXXVII. Proceedings of Learned Societies : — 



Royal Society : — Dr. J. W. Mallet on the Gases occluded 

 in Meteoric Iron from Augusta Co., Virginia; Mr. G. Gore on 

 some Properties of Anhydrous Liquefied Ammonia ; Mr. G. 

 G. Stokes on the Law of Extraordinary Refraction in Iceland 

 Spar 311-316 



XXXVIII. Intelligence and Miscellaneous Articles: — 



Report on a Memoir by MM. F. Lucas and A. Cazin, on the 



Duration of the Electric Spark, by Edm. Becquerel , 316 



On a new Galvanic Pile, of Economic Construction, by M. GaifFe. 320 

 On " Acoustical Experiments " &c„ by Alfred M. Mayer 320 



* 



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