EEPOET 



RECENT PROGRESS IN PHYSICS, 



BY Dr. JOH. MULLER, 



PROFESSOR OF PHTSICS AND TECHNOLOGT IN THE UNIVERSITi" OF FREIBURG. 



[Translated from the German for the Smithsonian Institution.] 



In the portion of the report published this year it has been con- 

 sidered proper to insert notes rendered necessary by later investigations 

 or discoveries. These are suitably indicated, and, as a matter of course, 

 "the author should not be held responsible for them. In no case has 

 the original been altered with the single exception noted last year, 

 p. 332. 



Geoege C. Schaeffer. 



FIFTH SECTION. 

 THE CHEMICAL EFFECTS OF THE CURRENT. 



§ 171. Daniel's researches on electrolysis. — It may be considered as 

 well established that the chemical decomposition produced by the gal- 

 vanic current is always proportional to the force of the current, and 

 yet a more accurate examination of the electrolysis of different bodies 

 has disclosed phenomena which cannot satisfactorily be made to accord 

 with this law. If the current passes at the same time through a tan- 

 fgent compass, and through a voltameter, the quantity of detonating 

 gas evolved is always proportional to the tangent of the angle of de- 

 flection, whether the fluid in the voltameter be diluted sulphuric acid, 

 or a solution of phosphoric acid or of sulphate of soda. Casselman 

 has proved this by a series of accurate experiments in the treatise 

 already mentioned several times. 



This seems, at the first glance, to agree completely with the law of 

 constant electrolytic action ; but the solution of salt was also decom- 

 posed, the acid accumulated at the positive, and the base at the nega- 

 tive pole, and consequently, in addition to the decomposition of water 

 corresponding to the force of current, a part of the salt was also 

 acted upon. 



Daniell was the first one who accurately observed and investigated 

 this phenomenon. — (Philos. Transact., 1839, part I, page 9*7 ; 1840, 

 part I, page 209 ; Pog. An., 1842, sup. vol. p. 565 and p. 580.) 



