178 



and especially if the mercurial surface is in the form of a narrow 

 strip about -J-th of an inch wide, strong vibrations occur ; and sym- 

 metrical crispations of singular beauty, accompanied by definite 

 sounds, are produced at the mutual surfaces of the liquid metal and 

 electrolyte. 



In my experiments the crispations and sounds were readily pro- 

 duced by taking a circular pool of mercury from 1 to 3 inches in 

 diameter, surrounded by a ring of mercury about ^th or ^th of an 

 inch wide, both being contained in a circular vessel of glass or gutta 

 percha, covering the liquid metal to a depth of about -J an inch with 

 a rather strong aqueous solution of cyanide of potassium, connecting 

 the pool of mercury by a platinum wire with the positive pole of a 

 battery capable of forcing a rather large quantity of electricity through 

 the liquid, and connecting the ring of mercury with the negative pla- 

 tinum wire. The ring of mercury immediately became covered with 

 crispations or elevated sharp ridges about ^th of an inch asunder, 

 all radiating towards the centre of the vessel, and a definite or musical 

 sound was produced capable of being heard, on some occasions, at a 

 distance of about 40 or 50 feet. The vibrations and sounds ceased 

 after a short time, but were always reproduced by reversing the 

 direction of the electric current for a short time, and then restoring 

 it to its original direction. The loudness of the sound depends 

 greatly upon the power of the battery ; if the battery was too strong 

 the sounds did not occur. The battery I have used consists of 10 

 pairs of Smee's elements, each silver plate containing about 90 square 

 inches of immersed or acting surface ; and I have used with equal 

 success six Grove's batteries, arranged either as 2 or 3 pairs, each pla- 

 tinum plate being 6 inches long and 4 inches wide. If the cyanide 

 solutionwas too strong, the sounds were altogether prevented. 



Being occupied in investigating the conditions and relations of this 

 phenomenon with the intention of submitting a complete account of 

 the results to the notice of the Royal Society, I refrain from stating 

 further particulars on the present occasion. 



April 18, 1861. 



Major-General SABINE, R.A., Treasurer and Vice-President, 

 in the Chair. 



