PRE FA CB. 



The folloii'iiig ''First Scries" of lectures, as noiv printed, 

 contain part of the material of a conrse of tivelve lectnres 

 on '^ Animal Electricity," delivered at the Royal Institntion 

 (in ring the spring of iSgy. 



The six printed lectnres are by no means co-extensive 

 with the tivelve spoken lectnres. The former, more especially 

 the fifth and sixth, inclnde matter that I sJiould have felt 

 it impossible to consider at length in the face of a non-tech- 

 nical andience, bnt that I nevertheless regard as essential 

 to the fnrther study of the snbject. The latter icere of necessity 

 largely diluted ivith elementary explanations, and included 

 three lectnres on the electromotive action of the heart, and 

 on the action of nitrons oxide, the pnbtication of which is 

 reserved for a '^ second series" 



In Physical Science the Royal Institntion of Great 

 Britain has played a iisefnl as well as a brilliant part 

 as an organ of pnblic instrnction ; and the great physicists, 

 who fashioned the fntnre destinies of the Institntion, did 



