December 30, 1910] 



SCIENCE 



967 



with rise in temperature, due to a broadening of 

 the absorption band in the violet. This rapid 

 broadening of the absorption band into the visible 

 spectrum makes the cerium oxide a more efficient 

 radiator of light than it would be if it did not 

 have this property. The conclusion reached was 

 that the radiation from the gas mantle is a 

 thermal phenomenon, not requiring the introduc- 

 tion of catalytic action to explain the observa- 

 tions. 



Some Bugbears in Calorimetry : Dr. W. P. White, 



of the Geophysical Laboratory of tlie Carnegie 



Institution of Washington. 



The speaker briefly mentioned the fundamental 

 principles upon which the accuracj' in calorimetry 

 depends, and stated that during the last four 

 years the accuracy had increased tenfold. The 

 principal bugbear in calorimetry is the cooling 

 correction. This correction was discussed at some 

 length and the things heretofore considered essen- 

 tial in connection therewith were mentioned. By 

 taking advantage of these the cooling correction 

 is easily handled. The lag, and the error due to 

 it, were then discussed, this question being inves- 

 tigated here in Washington for the first time and 

 with the result that there is now no error left 

 due to this cause. 



In speaking of the error in the measurement 

 of the temperature (now the only real error re- 

 maining) the different kinds of thermometers 

 that had been employed were mentioned. Difl'er- 

 ent types of calorimeters were described and one 

 form was exhibited for inspection. Diagrams 

 were shown giving some results in which the 

 errors due to the cooling correction were negli- 

 gible. The final accuracy was 1/10,000 part. 

 R. L. Fabis. 



Secretary 



The 685th meeting of the society was held on 

 December 3, 1910, Vice-president Day in the 

 chair. Two papers were read: 



Explosions in Gaseous Mixtures: Mr. L. H. 

 Adams (by invitation), of the Geophysical 

 Laboratory of the Carnegie Institution of 

 Washington. 



The speaker described certain conditions under 

 which explosions in gaseous mixtures take place, 

 and spoke of the retarding effects of inert gases 

 on the explosion. Explosion is a reaction which 

 proceeds with increased velocity, and is accom- 

 panied by a rise of temperature, the ignition 



point depending on the heat capacity. Causes of 

 mine explosions were briefly discussed, the speaker 

 also pointing out that it would be of great value 

 to be able to predict the explosive conditions of 

 the air in mines. 



Explosive experiments with methane mixed with 

 air and carbon dioxide were described and the 

 conditions of explosion explained, and the per 

 cent, of methane defining the upper and lower 

 limits of explosion were given, this being also 

 illustrated by a diagram. In studying how inert 

 gases retard explosion, the explosion wave had 

 been looked into. 



The Melting and Boiling Points of some of the 



Cheniieal Elements: Dr. G. K. Bubgess, of the 



Bureau of Standards. 



The status of our present knowledge of the best 

 values to assign to the melting and boiling points 

 of the elements was illustrated by means of a dia- 

 gram representing their periodic distribution in 

 terms of atomic weights, and on which was also 

 indicated graphically, in the case of the melting 

 points, the outstanding uncertainty of each of 

 these temperatures. 



The several optical methods used for deter- 

 mining the higher temperatures were described 

 and their relative merits compared, and the re- 

 sults of some of the recent investigations were 

 discussed in some detail. 



The availability, reliability and reproducibility 

 of the various melting and boiling temperatures 

 of the elements which are used as fixed points, or 

 standard temperatures in thermometry, were also 

 discussed. 



Finally, after showing that the most probable 

 value on the constant volume gas scale of the 

 sulphur boiling point is 444°.70 ± 0°.08 from all 

 of the available data, there was given a descrip- 

 tion of the behavior of boiling sulphur, the 

 method and apparatus employed for realizing a 

 constant temperature in its vapor, including also 

 an account of the explorations of the temperature 

 distribution within the 30 cm. column of sulphur 

 vapor, and within radiation shield, of the usual 

 form of S.B.P. apparatus.' Use was made of 

 various types of thermo-electric and resistance 

 thermometers, the smallest of the latter being 

 9 mm. in length and of 13.1 u resistance in sul- 

 phur, capable of being read accurately to 0°.01 C. 

 The sulphur vapor was found to be of a tempera- 

 ture constant to ©".OS C. throughout 27 cm. of 



' See Waidner and Burgess, Bull. Bureau of 

 Standards, 6, pp. 149-230, 1910. 



