34 Electrical Researches by T)e la Rive and Gassiot. 



duction coil, and some remarkable results were obtained by 

 the introduction of tubes of distilled water into the circuit- 

 In this manner the number of striae could be with absolute 

 certainty controlled, the apparently continuous discharge of the 

 battery eliciting the same phenomena of stratifications as the 

 induction coil. Mr. Gassiot's paper, after describing many 

 original and curious experiments, concluded as follows : — 



" The form, or figuration of the striee, and the positions 

 they occupy in the vacuum-tube, appear by these experiments 

 to depend upon two separate and distinct conditions : — • 



" 1st. The power or energy of the battery. 



" 2nd. The state of tension of the highly attenuated matter 

 through which the discharge is visible. 



" The stria3 can be controlled, their number increased or 

 reduced, and their places or positions in the tubes altered by 

 the introduction of measurable amount of resistance in the 

 circuit; and thus they appear to indicate the amount of force 

 of tension which exists in a closed circuit of the battery, as the 

 divergence of the gold leaves of an electroscope denotes the 

 evidence of tension before the circuit is completed. v 



"In my former communications to the Royal Society I 

 have alluded to the direction of a force in the induction dis- 

 charge from the positive towards the negative (Phil. Trans. 

 1858, p. 16, sections 57, 58). 



" In 1859 I observed that there was also a tendency or in- 

 dication of a force emanating from the negative wire (Phil. 

 Trams. 1859, pp. 140, 142, 153, sections 68, 72, 99) ; the 

 actual disruption of the particles from the negative terminal 

 also indicates a force ; and this disruption is as freely obtained 

 by the continuous discharge of the battery (§ 16) as it is by 

 the intermittent discharge of the induction coil. 



' I have always observed that with the lowest state of in- 

 tensity with which the discharge can be obtained from an in- 

 duct ion coil, the stria3 are wider apart, and the dark space 

 bet ween the positive and the negative is much extended ; under 

 sonic conditions of the discharge it is the negative, and not 

 the positive, that assumes the dominant character. 



''I lie form of the stria3 in the battery discharge, as ob- 

 rved in No. 815, figs. 7, 8, and 9,* presents an appearance 

 somewhat analogous with the stationary undulations which 

 exist in a column of air when isochronous progressive undula- 

 ,|,,n ""'I Bach other from opposite directions, and on the sur- 

 face of uadr by mechanical impulses similarly interfering with 

 each other. 



" May not the dwrk bands be the nodes of undidations arisimj 



* Tlipso figures arc published in Proceedings of the Royal Society for Decem- 

 ber 11th, 186§. 9 



