62 CUBBENT FORCE CHAP. VI. §. I. 



experiments undertaken for the purpose of ascer- 

 taining the comparative sensibility of the galva- 

 nometer and the galvanoscopic frog, found, that 

 when the frog's limb was so arranged that the 

 feet were placed in one vessel containing water, and 

 the lumbar nerves in another vessel, then upon 

 completing the circuit with the galvanometer an 

 effect was produced upon the needle indicating a 

 current to pass from the feet to the upper part of 

 the limb ; the electrode in the vessel containing the 

 nerves being positive to the other. This he called 

 the proper current of the frog, a term by which it is 

 designated at the present day, and he considered 

 that the effects were thermo-electric in their nature. 



Matteucci subsequently pursued the subject, and 

 amongst other most important results he ascertained, 

 that when a muscle was divided and one electrode 

 placed in contact with the divided surface, and the 

 other in contact with the external smface, an effect 

 was produced upon the needle. He further shewed, 

 that this effect depended upon the vital condition of 

 the muscle, upon the state of its nutrition. 



After the publication of Matteucci's earlier ex- 

 periments, Du Bois Eeymond took up the subject, 

 and from a series of ingenious experiments deduced 

 what he designated as the law in regard to the 

 miiscular current, viz. that any point of the longitudinal 

 section or the surface of the muscle was positive to 

 any portion of the tramverse section, whether natural 

 or artificial, of the same muscle. Finding, however, 



