348 



Presents. 



[Feb. 2, 



The spectrum exhibits the appearance of a series of rhythmical 

 groups more or less overlapping one another, and the arrangement of 

 the lines in these groups is shown to follow, in many cases, the law 

 that the distances between the lines, as measured in wave-lengths, are 

 in an arithmetic progression. M. Deslandres had previously announced 

 that the succession of lines in A, B, and a follow this law when 

 their distances are measured in reciprocals of wave-lengths, and he has 

 stated that the groups A, B, and a, have counterparts in the spectrum 

 of water. The authors find a striking resemblance between those 

 groups and certain parts of the water spectrum, but no exact corre- 

 spondence. 



Dr. Grriinwald, of Prague, predicted on theoretical grounds that 

 certain lines would appear in the spectrum of water, and the authors 

 have found a considerable number of lines which tally closely with 

 Dr. Griinwald's predictions, some of them, in the extremities of the 

 spectrum, being the strongest lines observed in those regions. 



III. " On the Voltaic Circles producible by the mutual Neutrali- 

 sation of Acid and Alkaline Fluids 5 and on various related 

 Forms of Electromotors." By C. R. Alder Wright, D.Sc, 

 F.R.S., Lecturer on Chemistry and Physics, and C. Thomp- 

 son, F.I.C., F.C.S., Demonstrator of Chemistry, in St. 

 Mary's Hospital Medical School. Received January 18, 

 1888. 



[Publication deferred.] 



Presents, February 2, 1888. 



Transacti6ns. 



Bern : — Naturforschende Gesellschaft. Mittheilungen. Jahrgang 

 1885. Heft 3. 8yo. Bern 1886. ~ The Society. 



Briinn : — Naturforschender Verein. Verhandlungen. Band XXIV. 

 Hefte 1-2. 8vo. Briinn 1886 ; Bericht der Meteorologischen 

 Commission fur 1884. 8vo. Briinn 1886. The Verein. 



Brunswick : — Verein fur Naturwissenschaft. Jahresbericht 3-4. 

 8vo. Braunschweig 1883, 1887. The Verein. 



Cambridge, Mass. : — Harvard College. Museum of Comparative 

 Zoology. Annual Report. 1886-7. 8vo. Cambridge 1887. 



The Museum. 



Harvard University. Bulletin. October, 1887. 8vo. [Cambridge"]. 



The University. 



Catania : — Accademia Gioenia di Scienze Naturali. Processi 

 Verbali. 1887. Nos. 1-2. 4to. [Catania]. The Academy. 



