132 Mr. Sturgeon on Electro-pulsations and Electro-momentum 



oradually improving facilities of internal and external commu- 

 nication, our American brethren may look forward to the at- 

 tainment of a state of greatness and prosperity that may not 

 readily lie within the compass of human calculation. 



XXX. On Electro-2mlsatwns and Electro-momentum. By 

 William Sturgeon, Lecturei- on Experimental Philosophy 

 at the Honourable East hidia Company's Military Academy, 

 Addiscombe, Sfc* 



IT is very well known to the readers of the Philosophical 

 Magazine, that I have long considered electric currents) 

 when transmitted through inferior conductors between the 

 poles of a voltaic battery, as the effect of a series of distinct 

 discharges, in such rapid succession as not to be individually 

 distinguished by the senses. Such currents I have called 

 electro-pulsatory. See my theory of magnetic electricity in 

 the London and Edinburgh Philosophical Magazine, vol. ii. 

 p. 202. 



By following up these views of electro-pulsations, I was 

 about two years ago enabled to dispense with all acid or sa- 

 line liquids, in the employment of galvanic batteries, for the 

 purpose of galvanizing, as it is called, either to satisfy the cu- 

 riosity or as a medical process ; and my plan, which answers 

 very well, I have found to be productive of a considerable 

 saving in the expense necessarily attendant on the use of 

 voltaic batteries when excited by acid solutions. 



It is well known that a Cruickshank battery of about a hun- 

 dred pairs will, by employing water alone in the cells, charge 

 to a certain degree of intensity almost any extent of coated 

 surface of glass that we please ; and that the same degree of 

 charge is given to it by a single contact of the conductors, 

 however short its duration. This being understood, and un- 

 derstanding also that the shock produced by any discharge 

 from a given intensity would be proportional to the quantity 

 of fluid transmitted in a given time, it was easy to foresee that 

 a series of shocks in rapid succession might be produced by 

 some mechanical contrivance, and that the degree of force 

 might be regulated by varying the extent of coated surface. 



My first experiments were made with a hundred and fifty 

 pairs of three-inch plates, and about seven feet on each side 

 of coated glass ; and my apparatus for producing a rapid suc- 

 cession of shocks was one of Mr. Barlow's stellated electro- 



* Communicated by the Author. 



