Mr. G. Gore on the Nature and Qualities of Voltaic Currents. 403 



" On Perchloric Acid and its Hydrates." By Henry Enfield 

 Roscoe, B.A., Ph.D., Professor of Chemistry in Owens College, 

 Manchester. 



January 9, 1862. — Major-General Sahine, President, in the Chair. 

 The following communications were read : — 



"Preliminary Note on the Nature and Qualities of Voltaic Cur- 

 rents." By George Gore, Esq. 



1. In a recent paper "On the production of Vibrations and 

 Sounds by Electrolysis," I have shown that if a voltaic current of 

 suitable quantity from two Grove's or five Smee's elements is passed 

 by a mercury anode through a solution composed of 10 grains of 

 cyanide of mercury and 100 grains of hydrate of potash, dissolved 

 in 2-| ounces of hydrocyanic acid containing 5 per cent, of anhy- 

 drous acid, into an annular cathode of mercury about 2 or 3 inches 

 diameter and -1-th of an inch wide, visible and symmetrical vibrations 

 of the negative mercury, accompanied by definite sounds, are pro- 

 duced ; and the current becomes intermittent as long as the vibra- 

 tions continue, similar to a current made intermittent by means of 

 an ordinary break-hammer. 



2. If two voltaic currents of suitable and equal quantity (measured 

 by a voltameter in the circuit), the one being generated by about 

 eight Smee's elements of large immersed surface, and the other 

 generated by twenty Smee's elements of small surface, are passed 

 separately through the arrangement just described, vibrations and 

 sounds are in each case produced ; but with the current from the few 

 elements of large surface the amplitude of the vibrations is small 

 and the sound high, whilst with the current from the many ele- 

 ments of small surface the amplitude of the vibrations is large and 

 the sound base. These differences in the vibrations and sounds are 

 still more conspicuous if a galvanometer of small resistance {i. e. with 

 a short and thick wire) is substituted for the voltameter, and about 

 four Smee's elements employed instead of tbe eight. In each of 

 these experiments the voltameter (or galvanometer) is in the circuit 

 with the cyanide solution ; the quantities of the two currents are 

 made equal by suitably adjusting the relative depths of immersion of 

 the plates of the two batteries ; and each experiment (with the volta- 

 meter) occupies 3 minutes. The size of the mercury electrodes has 

 also been previously adjusted to the power of the current, so as to 

 give continuous definite vibrations and sounds. 



3. Further : — If a current from two Grove's or five Smee's ele- 

 ments of large surface is passed through a primary coil of about 

 250 feet of thick copper wire, through the cyanide solution and 

 small-resistance galvanometer, the vibrations are moderate in size 

 and the pitgh of the sound is moderately high ; but if the axis of the 

 coil contains a massive bundle of soft iron wires, the vibrations are 

 much larger and the pitch of the sound is much more base ; and if 

 the primary coil is surrounded by a secondary coil containing about 

 4000 feet of fine copper wire, the ends of which are closely united 



