Intelligence and Miscellaneous Articles, 317 



of the general form, 



In the application to the theory of probabilities, the form of the 

 function V depends upon the explicitly determined logical connexion 

 of the events in the data ; the equations or inequations of condition 

 correspond to the conditions of possible experience as a source of the 

 data. 



It appears, therefore, that, quite independently of any question of 

 the validity of the logical, and I ought perhaps to add philosophical, 

 grounds of the method, it is a perfect method of interpolation. The 

 analytical investigation, however, shows that, for the mere purpose of 

 interpolation, the process might be modified by altering the coefficients 

 of V without affecting its form ; but it indicates at the same time that 

 such modifications have no definite analogy with that process by which 

 weight is assigned to astronomical observations, and, from their arbi- 

 trary character, lead to results which cannot properly be regarded as 

 expressions of probability in any sense. 



XLIII. Intelligence and Miscellaneous Articles, 



ON THE STRATIFICATION OF THE ELECTRIC LIGHT. 

 BY M. REITLINGER. 



MREITLINGEPv has proposed, in a note presented to the Aca- 

 • demy of Sciences of Vienna (January 3, 1861), anewexplana- 

 tion of the phenomenon known under the name of the stratification of 

 the electric light, which he has imagined from some of the results of 

 his observations on Geissler's tubes. A great number of these tubes 

 are formed with large and narrow portions alternately, and emit differ- 

 ent colours of light in the two portions when they are traversed by 

 an electric discharge. This curious phenomenon has probably been 

 perceived by most of those who have experimented on the electric 

 light. M. von Ettingshausen found that the different luminous parts 

 have totally different constitutions, and intimated to M. Reitlinger 

 this particularity as an interesting subject for study. 



In front of a narrow slit, a rectangular prism is placed in a situa- 

 tion so that the lateral rays of light from some source may so come, 

 on being reflected entirely on the hypothenuse face, as to illuminate 

 the upper half of the slit, while the other half is illuminated by 

 direct rays from another source. 



It is possible in this manner to compare the spectra of the two 

 lights and perceive their identity or their differences. M. Reitlinger 

 has found that in this manner the spectrum of the narrow parts of an 

 undulating tube constructed by Geissler, and sold by him as a 

 hydrogen-tube, was the spectrum of pure hydrogen, while the spec- 

 trum of the larger parts was that of oxygen. The diversity of lights 

 consequently was owing to the diversity of the luminous substances ; 

 and the passage of the electricity appeared to separate from one 



