Critical Phenomena of Kilter. 



799 



judging the absence of permanent gas — namely, the absence 

 of bubbles in a capillary tube containing the ether — cannot 

 be relied upon if the ether is under a pressure approaching 

 that of the atmosphere. 



In some of the earlier tubes, the traces of gaseous impurit}^ 

 were more distinct after the tubes had been raised to a high 

 temperature than they were immediately after the process of 

 filling. Since the ether which was used in these tubes had 

 been kept for some months in a stoppered bottle placed in 

 a desiccator, it is possible that it had been attacked by the 

 atmospheric oxygen with the formation of products which 

 decomposed at a high temperature. In filling the later 

 tubes, the ether to be used was finally distilled over potassium 

 and sodium alloy within an hour or two of the process of 

 filling. 



Fig. 3. 



A 3 <t 0> R C, 



The following rather drastic method of filling the tubes 

 was finally found necessary. The tubes to be filled (A, B, C, 

 and D in fig. 3) were fused to a horizontal tube E, from 



