380 Professor Owen's Addrese. 



a further step by showing that, under the conditions or arrange- 

 ments of Galvani's experiments, the muscles would contract, 

 whether the electric current had its origin in the animal body, or 

 from a source external to that body- Galvatri erred in too exclu- 

 sive a reference of the electric force producing the contraction to 

 the brain of the animal : Volta in excluding the origin of the 

 electric force from the animal body altogether. The determina- 

 tion of " the true " and " the constant " in these recondite phe- 

 nomena, has been mainly helped on by the persevering and in- 

 genious experimental researches of Mateucci and Du Bois Rey- 

 mond. The latter has shown that any poins of the surface of a 

 muscle is positive in relation to any point of the divided or trans- 

 verse section of the same muscle ; and that any point of the surface 

 of a nerve is positive in relation to any point of the divided or 

 transverse section of the same nerve. Mr. Baxter, in still more 

 recent researches, has deduced impor: ant conclusions on the origin 

 of the muscular and nerve currents has been due to the polarized 

 condition of the fibre, and the relation of that condition to changes 

 nerve or muscular which occur during nutrition. From the pre- 

 sent state ofneuro-electricity, it maybe concluded that nerve force 

 is not identical with electric force, but that it may be another 

 mode of motion of the same common force-: it is certainly a polar 

 force, and perhaps the highest form of polar force : 



A motion which may change, but cannot die ; 

 An image ef some bright eternity. 



CHEMISTRY, PHOTOGRAPHY. 



The present tendency of the higher generalizations of Chemistry 

 seems to be towards a reduction of the number of those bodies 

 which are called " elementary" ; it begins to be suspected that 

 certain groups of so-called chemical elements are but modified 

 forms of one another ; that such groups as chlorine, iodine, bro- 

 mine, fluorine, and as sulphur, selenium, phosphorus, boron, may 

 be but allotropic forms of some one element. Organic Chemistry 

 becomes simplified as it expands ; and its growth has of late pro- 

 ceeded, through the labours of Hofmann, Berthelot, and others, 

 with unexampled rapidity. An important series of alcohols and 

 their derivatives, from amylic alcohol downwards ; as extensive a 

 series of ethers, including those which give their peculiar flavour 

 to our choicest fruits ; the formic, butyric, succinic, lactic, and 



