Chemistry and Physics. 11 



formation of a Standard List of Abbreviations of titles of Chemi- 

 cal Periodicals. The committee give the nine principles by which 

 they were governed in compiling the Provisional List of Abbre- 

 viations which-^ccompanies the report. This list gives proposed 

 standard abbreviations of 206 chemical periodicals (including 

 some of general science) for adoption by chemists with a view to 

 securing uniformity. Those desiring copies of this list can obtain 

 them by addressing the chairman of the committee, care of the 

 Smithsonian Institution. 



Tbe report also gives a list of the Indexes to chemical litera- 

 ture published to date, twenty in number. The committee is now 

 constituted as follows : II. Carrington Bolton, Chairman, F. W. 

 Clarke, Albert R. Leeds, Alexis A. Julien, John W. Langley, 

 Samuel H. Scudder, and C. K. Wead. 



7. 3fechanical Equivalent of Heat. — Dr. Dieterici employing 

 the electrical method for the determination of the mechanical 

 equivalent of heat, obtains as the results of his series of measure- 

 ments, 424-4 and 424-2. The highest and lowest values differ 

 very little from the mean of the determinations. The value of 

 the specific heat of water taken was the mean of the determina- 

 tions between 0° C. and 100° C. The author believes that the 

 specific heat of water can best be determined by the electrical 

 measurement of the mechanical equivalent of heat. — Nature, Nov. 

 10, 1887, p. 48. j. T. 



8. Radiation in absolute measure. — Mr. J. T. Bottomley 

 placed a wire in a blackened copper cylinder which was exhausted 

 of air. The wire was heated by an electric current and the 

 amount of energy measured which was necessary to maintain the 

 wire at a constant temperature. The constant temperature was 

 shown by the constancy of the resistance of the wire. The en- 

 ergy was measured by obtaining the value of the current and the 

 difference of potential. The measurements were obtained at such 

 a low pressure that a further reduction of this pressure did not 

 appreciably affect the energy given off. By means of an asymp- 

 totic curve the energy given off by radiation was then calculated. 



The energy radiated, expressed in gram -water Centigrade 

 units, was at 408°, 378-8 X10~ 4 ; at 505°, 726-1 X10 -4 . Two equal 

 wires of platinum were enclosed by melting in two equal cylinders. 

 One of these wires was covered with lamp black. By a suitable 

 arrangement both wires were raised from a red to a white heat by 

 known electrical currents and known differences of potential. 

 It was seen that the temperature of a dull body must be much 

 higher than that of a polished one in order to exhibit the same 

 brightness. — Proc. Roy. Soc. Lond., xlii, pp. 357-359, 1887 ; ibid., 

 pp. 433-437. j. t. 



9. Maximum of Light Intensity in the Solar Spectrum. — G. 

 Mengaeini after a careful study concludes that the relative 

 brightness of different colors of the spectrum changes, and the 

 maximum of the intensity of light is not in any fixed position. 

 It varies between tolerably wide limits. — Rend, della R. Ace. dei 

 Lincei (4) iii, pp. 482-489, 1887. j. t. 



