Chemistry and Physics. 519 



one is the strongest, and three bands in the green-blue, weaker 

 than the others. From wave-length 5268 the general absorption 

 rises to 5203, becoming total for the more refrangible region 

 beyond this. The wave-lengths of the six bands characteristic of 

 nitrosyl chloride are given as 6228-6183, 6068-5970, 5808-5843, 

 5634-5000, 5432-5581 and 5411-5363. — Zeitschr. Phys. Chem. t iv, 

 121 ; Ber.Berl Chem. Ges n xxiii, (Kef.) 171, Moh. 1890. g. f. b. 



3. A Dictionary of Applied Chemistry ; by T. E. Thorpe, 

 assisted by eminent contributors. In three volumes. Vol. I, 

 London, 1890 (Longmans, Green & Co.). — In a notice of the new 

 edition of Watts's Dictionary of Chemistry in a recent number 

 (vol. xxxviii, 409) attention was called to the fact that the plan, 

 that had been adopted, contemplated a companion work which 

 should deal with the application of chemistry to the arts. The 

 first volume of this work has now appeared, under the able edit- 

 orship of Professor Thorpe and well fulfills the promises that 

 were made for it. The subject matter differs in this case from 

 that treated of in the work on theoretical chemistry in that the 

 variety and mass of material is less great and hence the necessity 

 for compression and the great amount of abbreviation does not 

 exist, which it must be confessed is a relief to the reader. The 

 wide range of topics has been handled by a series of workers, 

 eminently qualified for the task they have undertaken, and the 

 combined result of their labors with those of the chief editor is 

 one of the best works of reference ever presented to the English- 

 reading public, one w r hose completeness and accuracy leave little 

 to be desired. 



4. Method of obtaining the oscillatory discharge used by 

 Hertz. — H. Classen employs a blast of air which is blown be 

 tween the terminals of a Kuhmkorf coil. The glow of hot parti- 

 cles of metal is suppressed and a sharp crackling spark suitable 

 for the repetition of Hertz's work takes its place. A blast of 

 steam answers the same purpose. — Wied. Annalen der Physik, 

 No. 4, 1890, p. 647. j. t. 



5. Oscillatory discharge of the Ruhmkorf coil. — M. R. Col- 

 ley discusses the theory of the Kuhmkorf coil with reference to 

 the problem of mutual induction. He introduces coils into the 

 circuit in order to modify these factors and studies the character 

 of the discharges of the Kuhmkorf coil through Geissler tubes 

 by means of a revolving mirror. The changing nature of the 

 stratification of the luminous tubes is an indication of the charac- 

 ter of the oscillatory discharge. The experiments confirm the 

 conclusions deduced from the equations of the author. — Comptes 

 JRendus, March 31, 1890, p. 700. j. t. 



6. Application of Photography to the study of Superficial 

 Tension. — Prof. Smith described the method, (Royal Society 

 Edinburgh, March 11.) as follows : Ripples are set up on the sur- 

 face of the liquid by means of a tuning fork and the surface is 

 then photographed along with a suitable scale. The lengths of 

 the ripples can thus be obtained by micrometric measurements of 



