3 1 2 London Electrical Society. 



M emb. Elect. Soc, was read, in which allusion was made to the recent 

 serious accidents occasioned by lightning, and which suggested the 

 propriety of the Society's taking the matter into consideration, and 

 publishing some general directions as to the best methods of pro- 

 tecting churches and other elevated buildings. 



A paper from a member, Mr. Mackrell, was then read, detailing 

 the plan by which he had succeeded in obtaining ferric acid by 

 electrolysis. 



A paper by Henry Letheby, Esq., A.L.S., was read, detailing the 

 particulars of the dissection of a Gymnotus Electricus, and containing 

 reasons for believing that the electric energy originates in the brain 

 and spinal cord. In reference to the anatomy of the fish, the author 

 shows that the electrical organs are not super- additions of a peculiar 

 structure, but are the result of an increased development of the 

 aponeurotic termuscular septa, which become so arranged as to form 

 long tubes, running diagonally from within outwards, so that the 

 juxtaposition of these tubes produces laminae which run longitudinal 

 to the animal. The number of tubes in the entire organs is estimated 

 at upwards of half a million. The organ is supplied largely by the 

 spinal nerves ; the peculiar nerve of Hunter, called by Mr. Letheby 

 the posterior or dorsal branch of the fifth, is distributed entirely to 

 the muscles. The author then alludes to the well-known researches of 

 Williamson, Humboldt, Faraday, Walsh, Todd, Davy, Matteucci 

 and others, which have proved the analogy between the effects pro- 

 duced by electrical fishes, and those developed by our artificial com- 

 binations. He then goes on to trace the connexion between these 

 two divisions of the subject, and directs attention to two important 

 facts : — 1st, that the organs are made up of aponeurotic septa con- 

 taining an albuminous gelatinous fluid ; and 2ndly, that these are 

 furnished with a supply of nerves far exceeding the wants of the 

 parts for the purposes of life. Bearing in mind this latter fact, and 

 then alluding to the voluntary nature of the shock, to its annihilation 

 when the nerves are severed, to its increase when the nerves are 

 irritated, he concludes that the electric force originates in the brain 

 and spinal cord, and is concentrated or made tense in the organ 

 itself. He then gives a series of deductions to show that electricity 

 and vital energy are in a manner identical. 



This paper was illustrated by an elaborate series of drawings, and 

 also by anatomical preparations of the organ and the supplying 

 nerves. 



Mr. Weekes's Electro-Meteorological Report for July was then 

 read, from which we gather that while the metropolis has been so 

 seriously visited by lightning, the neighbourhood of Sandwich has 

 been comparatively tranquil. 



September 20. — The papers read this evening were, — 1st, 

 " Additional Notes on the Production of Acari, &c. in close Atmo- 

 spheres, incident to the operation of Voltaic Currents." By W. 

 H. Weekes, Esq., M.E.S. 



Mr. Weekes finds, from continued observation, that these insects, 

 whatever be their origin, are multiplied by the ordinary means of 



