406 Scientific Intelligence. 



city, which is transmitted to the plate, and the liquids which moisten 

 the fingers negative electricity. With the alkalies the effects are 



inverse." 



It follows from this, that if one of the plates is covered externally 

 by a very thin layer of hygrometric water, and if it is touched with a 

 finger moistened with perspiration, electric effects, resulting from the 

 reaction of the perspiration upon the water, ensue. It is also produced 

 when a finger in a great state of transpiration is applied upon one of 

 the plates, after having been previously moistened with water ; in this 

 case the water acquires positive electricity, and the contrary elec- 

 tricity flows into the body of the experimenter. If we add to these 

 effects those which take place when foreign bodies are adherent to the 

 skin, we must conceive that a large number of complex electric effects 

 would be produced in plunging two fingers, as is done by M- Du Bois 

 Reymond, into two capsules filled with water in which are contained 

 , two plates of platinum in communication with a multiplier. This is 

 not all : when, in virtue of these various causes, a current has circulated 

 in the liquid and in the wire, the two plates of platinum are polarized in 

 opposite directions, as may be shown by withdrawing the fingers and 

 establishing the communication between the two capsules by means of 

 a siphon filled with the same liquid as that which they contain. This 

 current, during the first few moments, having the same intensity as the 

 primitive current, annuls it ; but if, in the act of contraction, the finger 

 of the contracted hand become more or less immersed in water, the 

 inverse current may be less or superior to the direct current. 1 guarded 

 not only against the effects of the inverse current, but also against the 

 effects resulting from the greater or less immersion of the fingers, by 

 smearing with fat those parts of the fingers which might temporarily 

 come into contact with the liquid. By proceeding in this manner, I 



found it impossible to observe the effects described by M. Du Bois 

 Reymond. 



3. Note relative to the Electricity developed by Muscular Contrac- 

 tion ; by i\l. C. Despretz, (Ibid.) — The note which I have the honor 

 of communicating, is a simple enumeration of the experiments which I 

 made with the view of reproducing the phenomena announced by M. 

 Du Bois Reymond of Berlin.* I shall not discuss these phenomena, 

 my only object being to reproduce them. * * * * 



. The galvanometer which I used was made by M. Ruhmkorff, whose 

 skill is well known. The diameter of the wire was T yh of a millime- 

 tre, and its length 300 metres. The wire made about 1800 convolu- 

 tions round the frame of the apparatus. The delicacy of the instru- 

 ment is shown by the following numbers. 



A copper wire fths of a millimetre in diameter, when immersed 

 to a depth of two centimetres, afforded a deflection of 3 J in distilled 

 water, 25° in the water of the river Seine, and 68° in a solution of chlo- 

 rid of sodium, containing from four to five percent, of- the salt. 



Plates of gold, the surfaces of which were nearly one square centi- 

 metre, afforded under the same circumstances deflections of 11°, 24 

 and 85°. The gold, which was perfectly pure, had been recently pre- 



Comptes Rendus, May 21 ; and Phil Mag., vol. xxiv, p. 453 





