Dialytic Separation of Gases by Colloid Septa. 511 



thirds of the central portion of the porcelain tube, which could 

 be conveniently heated. The apparatus obviously affords the 



Fisr, 2. 



means both of heating the platinum in a vacuum and also in an 

 atmosphere of hydrogen or any other gas admitted into the in- 

 terior of the porcelain tube at M. 



Fused platinum. — Articles of manufactured platinum appear 

 now to be prepared exclusively from the fused metal. 



1. A quantity of clean platinum wire from fused metal, mea- 

 suring 0*695 metre in length, 4*1 millims. in diameter, and 201 

 grms. in weight, was bent and introduced into the porcelain 

 tube, which was then exhausted. The platinum was first heated 



