Intelligence and Miscellaneous Articles. 335 



tact of the surface of equal potential which touches the surface of 

 the water. — Comjptes Rendus de V 'Academic des Sciences, vol. lxxxii. 

 pp. 454, 455. 



ON THE METALLIC REDUCTIONS PRODUCED IN CAPILLARY SPACES. 

 BY M. BECQUEREL. 

 When a cracked tube containing a concentrated metallic solution 

 (of nitrate of copper or chloride of cobalt for example) is dipped 

 into a solution of monosulphide of sodium, if the crack is not suf- 

 ficiently narrow, diffusion is produced, giving rise to the production 

 of metallic sulphide in the solution of copper or cobalt; this sulphide 

 forms a coat adhering pretty strongly to the glass ; and then by 

 degrees a deposit of bright metal is seen to form in the molecular 

 space between the coat of sulphide and the glass, on the side of the 

 metallic solution. 



Similar effects are produced by applying to the crack, outside the 

 tube, a strip of paper covered with a layer of freshly precipitated 

 sulphide, fixing it to the surface by means of a wire wound round 

 it. Cobalt, copper, platinum, &c. have thus been obtained in the 

 metallic state ; the first was attracted by the magnet. 



Effects like these might indeed take place in organic nature in 

 the case of rupture of tissues or vessels. Suppose, for example, 

 that a vessel which traverses a muscle is ruptured at any point ; 

 blood is immediately diffused into the muscle ; and a coagulum is 

 formed, which is in contact on one side with the blood, on the other 

 side with the liquid that moistens the muscle. An electrocapillary 

 action will then take place resembling the foregoing, giving rise to a 

 reducing or oxidizing action, according to the nature of the liquid 

 with which the blood is in contact when it coagulates. The pro- 

 ducts then formed may cooperate in closing the aperture. I merely 

 indicate the forces which come into play, in the impossibility of 

 knowing what products are formed. 



Doubtless similar effects are produced in wounds covered with a 

 plaster coated with a substance of a healing nature. 



The communication finishes with a recital of the chemical reactions 

 produced in capillary spaces with the cooperation of a voltaic cou- 

 ple of two liquids, adjunct but forming part of the apparatus. The 

 couple is formed of a cracked tube containing a solution of mono- 

 sulphide of sodium, in which is immersed a slip of platinum ; and 

 it is introduced into a test-tube containing a metallic solution. 

 Thus arranged, the two-liquid couple operates in consequence of 

 the reaction of the two liquids in the fissure ; two currents result, 

 travelling in the same direction — one the current in question, the 

 other the electrocapillary current described in my previous memoirs. 

 On the other hand, the platinum wire wound rourd the tube touch- 

 ing the crack being the negative electrode at which the reduction is 

 effected, it follows that the two actions are added together, as can 

 readily be explained ; and thus the amount of reduction is doubled. 

 It is to be remarked that electrocapillary apparatus formed of 

 cracked tubes actonly so far as the two liquids, penetrating the 



