On some TJiermodynamical Relations . 255 



however, from conduction-resistance in the less important 

 circumstance that it varies in amount with the strength and 

 density of the current ; with a given electrolyte it is also 

 usually much larger in amount than the ordinary conduction- 

 resistance of a short section of that liquid : this appears* 

 consistent with the difference of conditions. 



From these various fundamental truths respecting it, 

 "transfer-resistance - " is a retarding influence essentially 

 similar to ordinary conduction-resistance, but modified, in- 

 creased in amount, and rendered more complex by taking 

 place at the surfaces of mutual contact of two heterogeneous 

 bodies instead of in the mass of a homogeneous substance ; 

 but whether it ought to be designated by some other term 

 than the one I have found it convenient to employ is a ques- 

 tion not yet settled. It is my intention, if I am not prevented, 

 to further investigate the subject. 



As the magnitude of this u resistance " to that of the mass 

 resistance in a given electrolytic or voltaic cell is usually 

 large, especially with non-corroded metals, it performs an 

 important part in the action of voltaic batteries and electro- 

 lytic cells. One important practical application of the fact 

 that u transfer-resistance " is usually diminished by enlarging 

 the electrodes, has been made in the electro-metallurgical 

 purification of copper on the large scale, where a great saving 

 has been effected by arranging the depositing-vats in "multiple 

 series." I have also shown (Phil. Mag. vol. xxi. 1886, p. 150) 

 that in consequence of diminution of " transfer-resistance " by 

 rise of temperature, with a voltaic element composed of zinc 

 and platinum in dilute suphuric acid, " the electromotive force 

 was increased about 8'38 per cent., and the strength of cur- 

 rent 220 per cent., or to 3*2 times its original amount, by 

 raising the temperature of the platinum negative plate 81 C. 

 degrees." 



XXXY. Note on the Paper on some Thermodynamical Relations 

 by Prof, W. Ramsay and Dr. S. Young. By Professors 

 W. E. Ayrton, F.R.S., and John Perry, F.R.S.* 



WE have written this note partly for the purpose of draw- 

 ing attention to the fact that, although scientific work 

 of many kinds is being much more thoroughly done now than 

 ever before in the history of the world, mainly because the 

 workers are specialists, yet a great deal of valuable work is 

 rendered comparatively useless because the specialist is now 



* Communicated by the Physical Society : read January 23, 1886. 



