NERVOUS FORCE. MEMORY. 147 



prove the analogy, if not the identity, of the electric and 

 nervous fluids. Naturalists and physicians have striven to 

 establish by the aid of experiment, that electricity is de- 

 veloped in the nervous centres and circulates in the nerves. 

 But up to the present time, the most delicate instruments in 

 the hands of the most skilful observers have failed to detect 

 in the nerves the slightest electric current, and nothing 

 authorizes us to consider the nervous force as identical with 

 electricity. May we not consider them as at least analogous? 

 They may both be developed by friction, by chemical com- 

 binations, by heat, &c. ; both are rapidly transmitted, and 

 both cause an elevation of the temperature, and the composi- 

 tion or decomposition of certain products. But while it is 

 true that motor impulses are transmitted with great speed, 

 comparable to that of the electric fluid, the nervous system 

 contributes only indirectly to produce animal heat, and nothing 

 here suggests a current heating a metallic wire. In fact it 

 is only by hypothesis that we assume the influence of nervous 

 force on the chemical operations of life, otherwise than in 

 giving activity to the organs intrusted with these operations. 

 But we must, notwithstanding, admit a certain analogy 

 between nervous phenomena and electrical phenomena. 

 Further research will doubtless throw light upon this ques- 

 tion, which is so eagerly studied, and which would perhaps 

 have already been solved if we could compare the reactions 

 of inert matter to the transformations of organized matter, 

 and the phenomena which are purely physical with those 

 in which life takes part. 



The memory. The Greeks made Mnemosyne the mother 

 of the Muses, and for us, under a less poetical form, me- 

 mory is the indispensable bond of union of the intellectual 

 faculties. 



The senses reveal to us the external world, the intellect 

 apprehends the sensations, and rising from material notions 

 to abstract conceptions, embraces all that man is permitted 

 to learn or to know; but it is the memory which enables us 

 to record, as in a book, facts and results, to compare and to 

 judge, to express thought by language, and to share the 

 thoughts of others. Without memory man would not recog- 



