472 SirB. C.Brodie on the Action of 'Electricity on Gases. [June 20 



the operator of being able to instantaneously cool and examine the assay 

 at any time, by dipping the whole in a cup of water. 



Aluminium foil as a support. 



89. It has been found that pieces or strips of aluminium foil not wider 

 three inches long, withstand the strongest heat of the pyrogene without 

 fusing as well as platinum does, over which the former metal possesses this 

 great advantage, viz. that many metals, as gold, silver, lead, &c, or their 

 alloys, may be fused upon it without the least fear of combination. 



It is thus possible to use this beautiful metal as a support upon which 

 to fuse most other metals, alloys, or metalliferous ores wrapped in a piece 

 of soda paper, instead of upon charcoal — the advantages being cleanliness, 

 portability, and even economy, for one strip will last out any number of 

 pieces of charcoal. It is rapidly attacked, however, by chlorides and phos- 

 phates. 



90. [Minerals heated in P. P. upon Al. foil afford extremely valuable 

 indications of some oxides, which on charcoal would be fused and reduced ; 

 as, e. g., Kupfer nickel and Speisscobalt, which thus immediately yield a 

 fine green oxide — "emerald nickel." (6th August, 1872.)] 



XV. "On the Action of Electricity on Gases. 33 By Sir B. C. Brodte, 

 Bart v E.R.S., Hon. D.C.L. Oxon._, late Wayneflete Professor 

 of Chemistry in the University of Oxford. Received June 6, 

 1872. 



(Abstract.) 



This memoir, which is intended to be the first of three communications 

 as to the action of electricity on gases, is devoted to the consideration of 

 the changes produced by the action of electricity on oxygen gas as estimated 

 by the changes thus effected in its chemical properties. 



The memoir is divided into four sections. 



Section I. contains an account of the methods employed for generating, 

 collecting, and preserving the electrized gas, and also of the measuring- 

 apparatus employed for estimating the changes in ihe volume of the 

 electrized gas effected in the various experiments subsequently described. 



The gas, carefully dried, was submitted to the action of electricity by 

 causing a current of the gas to pass through the induction-tube of Siemens, 

 the interior of which was filled with water or (where a low temperature 

 was desired) with a saline solution. The tube was placed in a glass cylin- 

 der containing water or a refrigerating-mixture. The interior and exterior 

 of the tube were respectively connected with the terminals of a powerful 

 Ruhmkorff's coil. The electrized gas, after its passage through the in- 

 duction-tube, was collected, in a gas-holder of peculiar construction, over 

 concentrated sulphuric acid. It may be thus preserved for several hours 

 without sensible variation in its properties. 



The principle employed for the measurement of the gas in which it was 



