1884.] On a New Method of Generating Electricity. 211 



thin sheet iron (two mcn ) was used in numerous experiments, but 

 this does not make a perfect arrangement when glass containing 

 alkali is used, as the alkali metal appears to be liberated at a very 

 strong heat. 



A uumber of metals were tried either in the form of sheet or as a 

 powdery deposit. 



This latter form might frequently be obtained by coating the 

 interior of the glass tube with the oxide of the metal to be tried, and 

 then reducing the metal by hydrogen or coal-gas upon the surface of 

 the glass. 



The following metals were tried and found to transmit hydrogen 

 and cause the production of electricity s — 



Platinum. Molybdenum. 

 Palladium. Copper. 

 Gold. Silver. 

 Iron. 

 Nickel. 



The relative transmitting powers were not, however, ascertained. 

 There can be little doubt that the property of transmitting hydrogen 

 at a red heat belongs to most, if not all, metallic bodies. 



In the course of the experiments it was observed that the glass 

 used was practically a non-conductor of electricity from one or two 

 galvanic cells when it was heated to redness in an oxidising flame. 



When, however, hydrogen was supplied to the glass either inside 

 or outside of the tube it at once became a good conductor of the 

 Current. 



It was found necessary to avoid using glass containing metallic 

 oxides reducible by hydrogen, as these oxides by reacting upon the 

 hydrogen on the surface of the transmitting plate cause frothing of 

 the glass, thus destroying that absolute contact between the metal 

 and the glass which is required for the production of the electric 

 current. 



Experiments were made with tubes of Berlin porcelain, and satis- 

 factory results were obtained. It was found convenient to cover the 

 surface of the tube both inside and out with melted glass and then to 

 carefully lay platinum foil upon the glass, so as to get as perfect an 

 adherence as possible. It appears to be best to have a much thicker 

 metallic plate on the inner side of the cell than on the outside. The 

 author has not determined the most advantageous conditions precisely 

 as yet. Cells were also constructed of clay, containing a percentage 

 of glass, porcelain of various kinds, &c. 



The amount of hydrogen transmitted in a given time through the 

 arrangements described varies greatly according to the nature of the 

 medium and the nature of the metallic layer. 



