1861.] 221 



quently feeble sounds are heard a few seconds before crispations 

 appear, and sometimes also a short time after they disappear, espe- 

 cially in a solution composed of 2f ounces of hydrocyanic acid, 100 

 grains of hydrate of potash, and 20 grains of cyanide of mercury. 

 In a weak solution of cyanide of potassium the sounds sometimes 

 cease or become inaudible before the elevations disappear; and in 

 other cyanide solutions I have occasionally observed the sounds and 

 crispations continue a short time after the electric current has been 

 stopped ; there is probably, therefore, a liquid metal and electrolyte 

 which together will emit sounds without the aid of a battery, and I 

 have made a few experiments (with Hg alloyed with K) to discover 

 them, but without success. In some cyanide solutions the sounds 

 and crispations cease very suddenly ; but in the one I have given (3) 

 they remain nearly uniform about ten or fifteen minutes with a feeble 

 electric current, and then diminish gradually as a film is formed upon 

 the anode. The crispations are more steady with a moderate number 

 of large voltaic elements than with a large number of small elements. 

 On some occasions, especially with many elements of small surface, 

 two sets of crispations, one about half the width of the other, will 

 coexist and succeed each other alternately. 



11. In every case the PITCH of the sound varied with the width 

 of the crispations ; the more base the sound, the greater was the 

 distance between the elevations. The loudness of the sound appeared 

 to depend partly upon the depth of the crispations ; but this point I 

 have not determined ; if the specific gravity of mercury was less, or 

 that of the solution greater, the crispations would probably be deeper 

 and the sounds louder. Shallow crispations formed upon mercury in a 

 solution of iodide of potassium evolved no perceptible sound, although 

 their width was about y^h ^ an mcn - No loud sounds have been ob- 

 tained. Rings of mercury 8 inches diameter gave no louder sounds 

 than rings 2^ inches diameter, although the quantity of electricity 

 circulating was much larger, the plates of the battery referred to (4) 

 being immersed 9 inches deep in the former case and only 1 inch in 

 the latter case. A certain amount of time is occupied in the deve- 

 lopment of the vibrations, and is distinctly observable where the elec- 

 tric current is feeble ; the vibrations and sounds being gradually deve- 

 loped as the mechanical resistances opposed by inertia, gravity, 

 cohesion, adhesion, friction, &c. of the liquids are gradually over- 

 come. The vibrations are attended by movements in the mass of 



