Historical and Personal 7 



On July i, 1773, Mr Walsh communicated to the Royal Society his 

 paper "Of the Electric Property of the Torpedo. In a Letter from John 

 Walsh, Esq., F.R.S., to Benjamin Franklin, Esq., LL.D., F.R.S., Ac. R. 

 Par. Soc. Ext., &c." 



The following extracts will indicate the chief points of electrical interest. 



The vigour of the fresh taken Torpedos at the Isle of Re was not able to 

 force the torpedinal fluid across the minutest tract of air; not from one link of 

 a small chain, suspended freely, to another; not through an almost invisible 

 separation, made by the edge of a pen-knife in a slip of tinfoil pasted on 

 sealing-wax. 



The effect produced by the Torpedo when in air appeared, on many repeated 

 experiments to be about four times as strong as when in water. 



The Torpedo, on this occasion, dispensed only the distinct instantaneous 

 stroke, so well known by the name of the electric shock. That protracted but 

 lighter sensation, that Torpor or Numbness which he at times induces, and from 

 which he takes his name, was not then experienced from the animal; but it 

 was imitated with artificial electricity, and shewn to be producible by a quick 

 succession of minute shocks. This in the Torpedo may perhaps be effected by 

 the successive discharge of his numerous cylinders, in the nature of a running 

 fire of musketry; the strong single shock may be his general volley. In the 

 continued effect, as well as in the instantaneous, his eyes, usually prominent, 

 are withdrawn into their sockets. 



Walsh shows that these phenomena " are in no ways repugnant to the 

 laws of electricity," for "the same quantity of electric matter, according 

 as it is used in a dense or rare state, will produce the different conse- 

 quences." 



Let me here remark that the sagacity of Mr Cavendish in devising and his 

 address in executing electrical experiments, led him the first to experience with 

 artificial electricity, that a shock could be received from a charge which was 

 unable to force a passage through the least space of air. 



Walsh concludes his letter to Franklin in the following terms : 



I rejoice in addressing these communications to You. He, who predicted 

 and shewed that electricity wings the formidable bolt of the atmosphere, will 

 hear with attention, that in the deep it speeds an humbler bolt, silent and 

 invisible: He, who analysed the electrified Phial, will hear with pleasure that 

 its laws prevail in animate Phials: He, who by Reason became an electrician, 

 will hear with reverence of an instinctive electrician, gifted in his birth with 

 a wonderful apparatus, and with the skill to use it*. 



* That the electrical fishes still possess the power of exciting the imagination as 

 well as the nerves of those who have felt their power may be seen from the following 

 passage with which Prof. Du Bois Reymond begins his account of experiments on 

 a living Malapterurus in the Monatsberichte d. k. Acad. Berlin, 28 Jan. 1858. 



"Fast mochte man es, im Sinne Newton's, eine Anwandlung der Natur nennen, 

 dass es ihr gefallen hat, aus der Unzahl der Geschopfe drei Fische, und zwar der 





