The Stratifications of Hydrogen. 40$ 



and when the hydrogen became visible the first line to appear was- 

 the red. 



That the change from parti -coloured stratifications to all pink i* 

 occasioned by an alteration in the intensity of the spark, is also shown 

 by the fact that altering the make and break of the coil produces the 

 same change as putting in the water resistance. Screwing up the 

 hammer-spring so as to induce strong magnetism in the core and high 

 potential of spark, gives pink and blue parti-coloured buttons. Weaken- 

 ing the spring, and thus weakening the magnetism, gives buttons 

 which are all pink. I cannot, however, in this way cause the migra- 

 tion of the blue buttons to one single button in front. This phe- 

 nomenon is produced only by an alteration of the exhaustion. 

 Conversely, an alteration of the exhaustion will not change parti- 

 coloured buttons to buttons of all one colour ; this requires a change 

 in electrical energy. 



I consider the water resistance acts thus : At the same rarefaction, 

 hydrogen conducts the current better than mercury vapour. With a 

 strong induction-spark at a certain degree of exhaustion, the conduct- 

 ing power of the rarefied hydrogen is not sufficient to carry the whole 

 of the current ; some of it, therefore, is conducted through the 

 mercury vapour, when the intensity of the blue drowns the feebler 

 colour of the hydrogen. When, however, a resistance of 6 inches of 

 water (equal to about 500,000 ohms) is inserted, the current is so 

 weakened that the hydrogen can carry the whole of it, and the blue 

 of the mercury is not seen. 



Conclusions ; Chiefly TlieorctiaiL 



The phenomenon of blue faces on the pink discs is probably due to 

 some such action as the following : At the exhaustion necessary to 

 give stratifications, there is a wide dark space round the negative pole. 

 Here the negative electrons (Radiant Matter), issuing from the pole 

 with enormous velocity, have sufficient energy to clear a space in front 

 of them to a distance varying with the degree of exhaustion. 



Dr. A. Schuster considers that the discharge through mercury 

 vapour in a vacuum tube, when quite free from air, will not give rise 

 to stratifications, nor to the dark negative space.* My own experi- 

 ments! show that the dark space will form in pure mercury vapour. 

 Whichever view may be correct, there is no doubt that if stratifica- 

 tions in mercury vapour are not altogether unknown, they are much 

 more difficult to produce than similar phenomena in hydrogen or other 

 diatomic gases. At a certain critical stage of the exhaustion, when 



* Dr. A. Schuster, "Experiments on the Discharge of Electricity through 

 Gusc.," ' Roy. Soc. Proc.,' vol. 37, p. 318. 



f ' Journ. of the Inst. Electrical Engineers,' vol. 20, p. 44. 



