Physics. — "TliP thermal conditctivity of neon." By S. Weber. 

 Suppl. N". 4c2b to the Conimnnioations from the Physical 

 Laboratory at Leiden. (Coinmuiiicated \)\ Prof. H. Kamehmngh 



Onnes). 



(Communicated in the meeting of Febr. 23, 1918). 



§ \. Introduction. In a coiiununioation by Prof. H. Kamehmngh 

 Onnks and lïjyself^) attention was drawn to the considerable devia- 

 tion fi-oin the hiw of corresponding states which shows itselt in the 

 comparison of the viscosity of ar^on and helium. This circum.stance 

 brought out the importance of an investigation of the viscosity ot 

 neon down to tiie lowest temperatures to be i-eaclied with this 

 substance. In this connection we al.so planned an investigation 

 of the heal conductivity of these gases at the lowest temperatures 

 to which measurements can be extended. Indeed according to the 

 kinetic theory a very close connection exists between internal friction 

 and conduction of heat. The two are only distinguished by a factor 

 (specific heat > numerical factor) and foi- monatomic ga.ses, where 

 the theory as regards viscosity is coufiriued in many respects, this 

 factor is independent of the temperature. According to the tiieory 

 of heat conduction and viscosity the same law of dependence on the 

 temperature will therefore be found in ihe two cases and it is im- 

 material vvhicli of the two quantities is submitted to investigation. 

 If both are measured, the results afford a means of mutual control. 



Personal circumstances allowed me, before the research above 

 sketched out could be cai-iied out at Leiden, t(» undertake the in- 

 vestigation of ihe heat conduction of gases in the physical labor- 

 atory of the Philips Incande.'icent Lamp Factories. It was there, that 

 the research contained in this communication was carried out. Only 

 that part whicii refers to the lowest temperatures will still have to 

 be peiformed at Leiden. 



The neon required for this investigation was put at my disposal 

 by Prof. Kameki.ingh Onnes. who had prepared it from a large 

 supply of gas-residue rich in neon presented to him by G. Claude ■'); 

 I am glad to offer him my sincere thanks. According to a commu- 



1) Leiden Comm. No. 134c April 1913. 

 «) Leiden Gomm. N'\ 147c p. 38. 



