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XII. Effect of Electricity on Streams of Water Drops. By 

 E. F. Burton, B.A., Associate Professor of Physics, Uni- 

 versity of Toronto, and W. B. Wiegand *. 



[Plate VI.] 



RECENT developments in Physics and Physiology have 

 accentuated the importance of the part played by 

 surface-tension in natural phenomena, and consequently 

 led to examination of the causes which appear to affect 

 materially the value of the surface-tension between two 

 given media. In particular, the study of colloidal solutions 

 has brought into prominence the inter-relation of surface- 

 tension and electrification. 



The purpose of the experiments outlined in the following- 

 paper was to examine the nature and causes of the well- 

 known effect of bringing a charged body into the neighbour- 

 hood of the spray of water issuing in a nearly vertical line 

 from a small nozzle. If a stream of water be directed 

 vertically to a distance of even several feet and then allowed 

 to fall on a sheet of metal, one recognizes the sound of the 

 falling water as that of small falling drops ; however, if 

 a charged body such as an ebonite paddle be brought gra- 

 dually near to the stream just at the point where it begins to 

 break into drops after issuing from the nozzle, the sound of 

 the falling water is unmistakably that due to much larger 

 drops than before. As has been already pointed out bv 

 Lord Rayleigh |, the falling water in the second case if 

 caught in an insulated dish will be found to be charged, a 

 phenomenon analogous to the Kelvin water-dropper. 



From time to time Rayleigh J has reported the results of 

 many beautiful experiments on this and the allied phenomena 

 of water-jets. Photographs (PL VI. figs. 1 & 2), taken instan- 

 taneously by the writers, represent well what happens in the 

 stream when the charged body is approached ; they are quite 

 similar to the photographs published some years ago by 

 Rayleigh. The stream was directed in a nearly vertical line 

 from a nozzle of glass, the opening of which was a circle of 

 a few millimetres diameter. Attention ma}^ be directed to 

 the following characteristics of these streams, which have 

 been illustrated time and again in photographs taken during 

 the progress of these experiments : — 



* Communicated by Prof. J. 0. McLennan. 

 f Sc. Papers, i. p. 372, § 59. 

 \ Sc. Papers, vols. i. to iv. 



