April 5, 1895.] 



SCIENCE. 



309 



This is a system of tolegraphj' from nerve- 

 ganglia, spine and brain which does not, as 

 liad been formerly supposed by some 

 writers, transmit energy, but simply indi- 

 cates where and when locally available 

 stored energj' is to be liberated and applied 

 to definite purposes by appropriate muscles. 

 It demands energy only in the manner and 

 in the degree in which the electric current fir- 

 ing a mine expends energy in the initiation 

 of the chemical action resulting in the tre- 

 mendous cflfects observed. The work is 

 done by the more or less complete transfor- 

 mation of the potential energy available in 

 chemical combinations into mechanical en- 

 ergy, once the electric spark fires the 

 charge. 



The passage of the electric current through 

 the fresh muscle produces the same efiects 

 as the nerve-impulse, and these etiects may 

 be reproduced again and again, until the 

 muscle loses its store of glycose or until its 

 structure changes. At every effort, the 

 flexed muscle consumes glj-cose and liber- 

 ates carbon-dioxide, precisely as iu its na- 

 tural operation under the stimulus of the 

 nerve-impulse. This parallelism of action 

 and effect may be taken as, perhaps, good 

 circumstantial evidence. In every animal 

 system, and in every mass of muscle within 

 it, electricity-leakage, or other movements 

 of electricity, may always be detected by 

 the familiar methods of the electrician, and 

 this everywhere distributed energy un- 

 questionably originates in the sj'stem itself, 

 and has place and purpose in its economj'. 

 In special cases, as in the gj^mnotus, Na- 

 ture has magnified its work and given it 

 larger place in the working of the machine 

 than ordinarily, and thus has given us an 

 opportunity to observe, on this magnified 

 scale of working, both the form of the special 

 constructions for the production of this form 

 of energy, and the method of its transmis- 

 sion and application. We find the electric 

 system of the gymnotus to be simply a 



development of the nerves and terminal 

 plates found in all animals. That they 

 have a common oflice. though very difterent 

 in relative magnitude and importance in 

 the two cases, is undoubted. That the 

 origin, however, of this form of energy, 

 simplj- as required for telegraphy, is chem- 

 ical is very certain, also, since it must find 

 its source iu the common store of potential 

 energj- supplied the whole sj'stem. That 

 this chemical process may be somewhat 

 different from that producing chemico-dy- 

 namic efl'ects is not imjirobable ; especially 

 as the presence of combustible fats of pecu- 

 liar composition seem always an essential 

 to nerve action. But all chemical action is 

 accompanied by electric phenomena, and 

 Xature here seems to make the fact sub- 

 servient to her plans. But she adopts 

 singular methods, and possibly a peculiar 

 form of this energj' ; and the minute quan- 

 tity detected by investigators, and the slow 

 rate of progress along the nerve fibers, are 

 elements of as yet unrevealed mystery. 

 The familiar exhausting effect of continued 

 nervous expenditure may be either due to 

 large energy expenditure or to restricted 

 supply of the special form of potential from 

 which it is derived. 



(6.) The nature, source and methods of de- 

 velopment and transformation of brain and 

 nerve power do not appear to have been yet dis- 

 covered, or ei'en surmised. 



The fact that such energ}' is subject to 

 exhaustion and renewal by preciselj' the 

 same processes, so far as can be obsers'ed, 

 certainly under the same conditions as pro- 

 duce fatigue or favor recuperation of mus- 

 cular power would seem to justify the in- 

 ference that the potential energy of the food 

 and the processes of nutrition and of devel- 

 opment of active physical energies in the 

 brain, spine and nerves are so modified in 

 these glands as to give a special product in 

 the form of vital energy, and perhaps of 

 brain-power, and of those initiative forces 



