62 London Electrical Society. 



After alluding to the original experiment of Mr. Crosse, and to 

 the objections made that the insects might have sprung from ova 

 in the atmosphere, Mr. Weekes states that he had resolved to pro- 

 vide against such contingencies. This he effected by placing the 

 solution, which was prepared with the utmost caution, beneath a 

 bell-glass, which has not been disturbed from Dec. 3rd, 1 840. Late 

 in October 1841 the first insect was detected; on Nov. 27th several 

 were seen : since then they are constantly to be seen, sometimes 

 solitary, at other times in pairs, and occasionally three or four to- 

 gether. The operation was conducted in the dark, light being only 

 admitted at those times when the progress was under examination. 

 The voltaic current was from a short series of Daniell's battery. 

 These creatures appear to love darkness ; for on the admission of a 

 ray of light they hasten away and seek hiding-places in the recesses 

 of the apparatus. Simultaneously with this another arrangement 

 was made, in which the current from a water battery was made to 

 pass through a solution contained in a bell-glass of oxygen. Insects 

 appeared in this on the 20th Feb. 1842, and eight or ten fine vigo- 

 rous Acari were visible. This is but a brief summary from a very 

 long and carefully written communication. The author assumes 

 nothing ; he does not venture to theorise, but gives a plain and ex- 

 plicit account of his experiments and of their results. The operation 

 is still going on, as there is every reason to expect a further deve- 

 lopment of insect life. More completely to preclude objections, he 

 is preparing another apparatus in which nothing but glass, metal, 

 and mercury (distilled from its sulphuret) will enter. 



2nd. " Note on Electro -tint, and on etching Daguerreotype 

 Plates." By W. G. Lettsom, Esq., M.E.S. 



This note was illustrated by specimens of tints produced by Prof. 

 Von Kobell of Munich, and Dr. Berres of Vienna. The former 

 has improved upon his original process of electro-tint by a method 

 of retouching the plates and then reobtaining others. 



3rd. Extracts of a letter from John Samo, Esq., of Surinam, 

 M.E.S. , containing " Information respecting the Gymnotus Electri- 

 cus." 



Among the specimens possessed by Mr. Samo were two in one 

 tub, whose relative lengths Were SO and 15| in. The smaller was 

 missed, and it was found that the other had swallowed it. He soon 

 however cast it up, and in the space of a few hours died. On post- 

 mortem examination it was found that the stomach was considerably 

 ruptured. Mr. Samo mentions that the report that a certain drug is 

 an antidote to the shock of the Gymnotus is without foundation. 



4th. The Secretary then communicated to the Society the death 

 of the London Gymnotus, which has from time to time furnished 

 such interesting results to Prof. Faraday, Dr. Schcenbein, Mr. Gassiot, 

 and others. 



5th. " On Voltaic Apparatus." By James P. Joule, Esq., M.E.S. 



The author details the results of a series of experiments upon local 

 action, and upon the relative intensities of several voltaic arrange- 

 ments under different circumstances. 



