212' 



Mr. J. A. Kendall. 



[Jan. 17, 



With, pulverulent metals and a medium of soft glass the rate of 

 transmission of hydrogen may be as high as 0*6 cub. centim. per 

 square inch per minute at a full red heat. With Berlin porcelain 

 tubes, however, the transmission does not usually exceed 0*2 cub. 

 ceutim. per square inch per minute, even at a white heat, while at a 

 red heat the rate is much lower. With platinum tubes of T ^ inch 

 thick the transmission may be from 0*1 cub. centim. to 0'2 cub. 

 centim. per square inch according to the temperature. 



The electromotive force of the new cells varies according to the 

 media used, and this subject will of course require further investiga- 

 tion. It was found, however, that the platinum tube cell gave, with 

 borate of lime at a nearly white heat, an electromotive force=0"36 of 

 a Daniell, whilst a cell constructed of Berlin porcelain tube T l Y inch 

 thick gave an electromotive force = 0" 7 of a Daniell when worked at a 

 nearly white heat. 



Although many gaseous mixtures containing free hydrogen will 

 serve to produce the electrical reactions, yet experiments with carbon 

 monoxide have given no similar result in conjunction either with iron 

 or platinum plates. 



In conclusion, the author has to thank Mr. S. A. Sadler, of Middles- 

 brough, for having put at his disposal various facilities for prosecuting 

 his later experiments. 



Received December 28, 1883. 



Before describing further researches which the author has made on 

 the subject of electrical currents produced by hydrogen, it may be 

 well to mention that the galvanometer generally used in the experi- 

 ments yet to be described, as well as in the former experiments with 

 metal tubes, &c, is one adapted for rather strong currents and it has 

 very slight resistance. It has been graduated by means of a volta- 

 meter. 



As these experiments must be regarded more as qualitative than 

 quantitative, it will perhaps be sufficient to give four points of deflec- 

 tion with the corresponding liberation of hydrogen in a voltameter. 



Deflection of Liberation of hydrogen 



galvanometer. per minute. 



10° 0-07c.c. 



20 0-21 „ 



30 0-60 „ 



40 1-35 „ 



The above figures also show, in a roughly approximate way, the 

 amount of hydrogen which must be supplied to a cell of the new con- 

 struction in order to give the deflection indicated. 



In continuing his researches the author has found that strongly 



