558 Scientific Intelligence. 



other hand, the helium line at A. 4472 did not follow a linear rela- 

 tion. The curves corresponding to this line are slightly concave 

 towards the axis of potential gradient. In conclusion, it may be 

 remarked that the laws governing lines belonging to the same or 

 to related series of the same element, or of different elements, 

 have been as yet only partially worked out, and hence any account 

 of their probable nature would be premature at the present time. — 

 Ann. d. Physik, vol. xliii, pp. 965-1047, April, 1914. h. s. u. 



9. Secondary Standards of Wave-Length in the Infra- Red.— By 

 means of a Fabry and Perot interferometer A. Ignatieff has 

 accurately determined the wave-lengths of one line of cadmium 

 and two of helium. A special monochromatic filter was used to 

 isolate the radiations under investigation. An account of the 

 composition and construction of absorption cells for long wave- 

 lengths is given by F. Paschen in the Annalen der Physik, No. 6, 

 March, 1914, pages 858-860. The helium line at A 10830 was 

 found to be double. By using an iron-constantan thermopile in 

 conjunction with a Paschen " Eisengalvanometer," and by plot- 

 ting curves having distances between the interferometer plates as 

 abscissas and galvanometer deflections as ordinates (method of 

 beats) the investigator found the separation of the components of 

 the helium doublet to be 1-21 ±0*01 A. U. The wave-lengths of 

 this doublet and of the two single lines were determined by two 

 methods, (a) "thermopile in central zone," and (b) the quenching 

 action of heat on a phosphorescent screen (phosphoro-photog- 

 raphy). The final results are 10394-66 ±0-02 Cd, 10830-32 ±0*01 

 He, 10839-11 ±0-02 He, and 20581*31 ±0-02 He. The numbers 

 following the double signs denote "possible" errors. — Ann. d. 

 Physik, vol. xliii, p. 1117, April, 1914. h. s. n. 



1 0. The Electrical Conductivity and Ionization Constants of Or- 

 (/tm?'c Co«^o«»i&; by Hetwaed Scuddee. Pp.568. New York, 

 1914 (D. Van Nostrand Co.). — The nature and scope of the con- 

 tents of this volume are made quite clear by the following quota- 

 tion from the author's introductory remarks. " The object of this 

 book is to present, . . . , a bibliography of all the measurements 

 of the ionization constants and the electrical conductivity of organic 

 compounds that have appeared in the periodical literature between 

 the years 1889 and 1910 inclusive, together with the values of the 

 ionization constants, and certain values of the electrical conductiv- 

 ity measurements." " Qualitative work is also included." " Be- 

 fore the year 1889, little work of value at the present time was 

 published." "All that is of value is included here." "From 1910 

 to the begining of 1913, important corrections that have come to 

 my notice have been inserted." " Beginning with 1910, full data 

 of the entire periodical literature are published in the Tables 

 Annuelles Internationales de Constantes et Donnees Numeriques." 



That the presentation is very complete and systematic may be 

 inferred from the following sequence of captions: Explanation, 

 Abbreviations, Cyclic Formulas, Tables (pages 42-322), Formula 

 Index (pages 323-389), Author List (2032 references), Subject In- 



