68 BEITISH ASSOCIATIOIS" POE 



nal surface of a muscle, when a contradiction of the muscle ensued. In this sugges- 

 tive experiment the Italian philosophei", who thereby initiated the inductive 

 inquiry into the relation of nerve force to electric force, concluded that the contrac- 

 tion was a necessary consequence of the passage of electricity from one surface 

 to the other by means of the nerve. He supposed that the electricity was secreted 

 by the brain, and transmitted by the nerves to different parts of the body, the 

 muscles serving as reservoirs of the electricity. Volta made a further step by 

 showing that, under the conditions or arrangements of Galvani's experiments, the 

 muscle would contract, whether the electric current had its origin in the animal 

 body, or from a source external to that body, Galvani erred in too exclusive 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 determination of "the true" and "the constant" in these recondite pheno- 

 mena, has been mainly helped on by the persevering and ingenious experimental 

 researches of Mateucci and Du Bois Reymond. The latter has shown that any 

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

 transverse section of the same muscle ; and that any point of the surface of a nerve 

 is positive in relation to any point ot' the divided or transverse section of the same 

 nerve. Mr. Baxter in still more recent researches, has deduced important conclu- 

 sions on the origin of the muscular and nerve currents, as being due to the polarized 

 condition of the nerve or muscular fibre, and the relation of that condition to 

 changes which occur during nutrition. From the present state of neuro-eleetricity, 

 it may be concluded that nerve force is not identical with electric force; but thatifc 

 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 chang;e, but cannot die : 

 An image of some bright eternity. 



The present tendency of the higher generalizations of Chsmistry seems to be to- 

 wards 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, bromine, 

 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 proceeded, through the labours of Hofmanu, Berthelot and 

 others, with unexampled rapidity. An important series of alcohols and their 

 derivatives, from amylic alcohol downwards ; as extensive a series of others in- 

 cluding those which give their peculiar flavor to our choicest fruits ; the formic, 

 butyric, succinic, lactic, and other acids, together with other important organic 

 bodies, are now capable of artificial formation from their elements, and the old 

 barrier dividing organic from inorganic bodies is broken down. To the power 

 which mankind may ultimately exercise through the light of synthesis, who may 

 presume to set limits ? Already natural processes can be more economically re- 

 placed by artificial ones in the formation ot a few organic compounds, the " vale- 

 rianic acid," for example. It is impossible to foresee the extent to which Chemis- 

 try may not ultimately, in the production of things needful, supersede the present 

 vital agencies of nature, "by laying under contribution the accumulated forces of 



