October 30, 1908] 



SCIENCE 



59c 



ment to be signed by the university authori- 

 ties and by the founder of the "Industrial 

 Fellowship" is suggested. 



In drawing this address to a conclusion 

 I can not but feel that my suggestions may 

 seem utterly inadequate to the attainment 

 of those important results which are so 

 greatly to be desired. If so, I can only 

 plead that more drastic measures are hardly 

 available, and that even under the most 

 favorable circumstances improvement can 

 take place only very slowly. Whatever 

 differences of opinion may be held as to 

 the details of any scheme for regaining our 

 lost ground, the main lines seem to be 

 clearly indicated. The workers in pure 

 science must recognize that it is their duty 

 to do all they can to promote the industrial 

 welfare of their country ; the manufacturers 

 must concede the paramount importance of 

 science and the impossibility of dispensing 

 with its counsels. Guided by these prin- 

 ciples and by a spirit of cordial coopera- 

 tion, a sustained and strenuous effort on 

 the part of the leaders of chemical industry 

 and of chemical science can hardly fail to 

 accomplish the end in view. 



A Determination of the Bate of Evolution 

 of Heat by Pitchblende: Horace H. 

 Poole. 



A spherical vacuum jacketed vessel with 

 a narrow neck is filled with powdered and 

 carefully dried pitchblende. The neck is 

 filled with cotton-wool and rendered water- 

 tight with sheet rubber, and the whole is 

 buried in ice. The diiJerence of tempera- 

 ture between the layer of pitchblende in 

 contact with the bottom of the vessel and 

 the ice is measured by a sensitive thermo- 

 couple. After about a fortnight this tem- 

 perature becomes steady, when the heat 

 leakage across the walls of the vessel is 

 equal to the heat generated by the pitch- 

 blende. The leakage depends solely on the 

 vessel and on the difference of temperature 



between inner and outer walls, which is 

 measured by the thermo-couple. The 

 thermal conductance of the vessel is foimd 

 by substituting water for the pitchblende 

 and determining its rate of cooling. Hence 

 the heat leakage is known, and, knowing 

 the amount of pitchblende present, the 

 heat evolution per gram is found. 



The thermo-couple is calibrated by 

 placing one junction in finely broken ice 

 and the other in a mixture of broken ice 

 and water, which can be subjected to a 

 known pressure. The deflection caused by 

 the resulting small change of temperature 

 is noted, and hence sensitiveness of couple 

 is found. 



Using 560.7 grs. of pitchblende in an 

 atmosphere of nitrogen, the temperature 

 finally steadied at 0.0092° C. As the ther- 

 mal conductance of the vessel is 5.8 calories 

 per hour per degree difference of tempera- 

 ture between inside and outside, this corre- 

 sponds to a heat leakage of 0.053 calorie 

 per hour. Hence heat evolution per gram 

 of pitchblende is 0.000094 calorie per hour. 

 This is about twice the quantity estimated 

 from the known amount of radium present. 



Do the Radio-active Gases (Emanations) 

 belong to the Argon Series? Sir Wm. 

 Ramsay, K.C.B., F.R.S. 

 The residues of the fractionation of 120 

 tons of liquid air obtained from Claude 

 were examined in the chemical laboratory 

 of University College by Professor Moore. 

 After removal of oxygen and nitrogen, 

 argon, krypton and xenon remained, and 

 were separated by methodical fractionation. 

 The xenon amounted to aboiit 300 cm.^; it 

 was methodically fractionated at — 130°, 

 and a final residue of 0.3 cm.^ was obtained. 

 The spectrum of this portion was photo- 

 graphed, and differed in no respect from 

 that of xenon. It is practically certain 

 that if this residue had contained 1 per 

 cent, of a denser gas, that gas would have 



