640 EVOLUTION OF HEAT, LIGHT, AND ELECTRICITY. 



673. Some of the most important parts of the body being thus in a state of 

 constant disequilibrium with regard to each other, it is not surprising that the 

 electric state of the whole should be ordinarily in disequilibrium with that of 

 surrounding bodies. This difference, however, is usually prevented from mani- 

 festing itself, in consequence of the restoration of the equilibrium by the free 

 contact which is continually taking place between them ; and it is for the most 

 part only when the Human body is insulated, that it becomes apparent. The 

 galvanometer is then affected, however, by the contact of one of its electrodes 

 with the person insulated, and the other with any neighboring uninsulated body ; 

 and also by the contact of the electrode with the hands of two persons both in- 

 sulated, who join their other hands together, a difference in the electrical states of 

 the two individuals being thus indicated. The electricity of man is most frequently 

 positive, and irritable men of sanguine temperament have more free electricity 

 than those of phlegmatic character; the electricity of women is more frequently 

 negative than that of men. There are persons who scarcely ever pull off articles 

 of dress which have 'been worn next the skin, without sparks and a crackling 

 noise being produced; especially in dry weather, when the electricity of the 

 body is retained, instead of being rapidly dissipated as it is by a damp atmo- 

 sphere. The effect is usually heightened, if silk stockings and other silken 

 articles have been worn, since these act as insulators. It is doubtless in part 

 attributable to the friction of the articles of dress against each other and against 

 the body; but we can scarcely doubt that it is partly due to the generation of 

 electricity in the body itself, since it bears no constant relation to the former 

 of these supposed causes. Thus a Capuchin friar is mentioned by Dr. Schnei- 

 der, 1 who, on removing his cowl, always found a number of shining crackling 

 sparks to pass from his scalp ; and this phenomenon continued still perceptible 

 after a three weeks' illness. The most remarkable case of the generation of 

 Electricity in the Human subject at present known, was recorded some years 

 since in America. 3 The subject of it, a lady, was for many months in an elec- 

 tric state so different from that of surrounding bodies, that, whenever she was 

 but slightly insulated by a carpet or other feebly conducting medium, sparks 

 passed between her person and any object she approached; when most favorably 

 circumstanced, four sparks per minute would pass from her finger to the brass 

 ball of the stove at the distance of 1^ inch. From the pain which accompa- 

 nied the passage of the sparks, her condition was a source of much discomfort 

 to her. The circumstances which appeared most favorable to the generation of 

 the electricity were an atmosphere of about 80, tranquillity of mind, and 

 social enjoyment; whilst a low temperature and depressing emotions diminished 

 it in a corresponding degree. The phenomenon was first noticed during the 

 occurrence of an Aurora Borealis; and though its first appearance was sudden, 

 its departure was gradual. Various experiments were made, with the view of 

 ascertaining if the electricity was generated by the friction of articles of dress; 

 but no change in these seemed to modify its intensity. 



quired a thorough mastery over the conditions of the phenomena. And he may mention 

 the experimental demonstration of the "nervous current," as most fully satisfactory. It 

 may be stated with confidence, that the course of investigation which is being followed out 

 by M. du Bois-Reymond, is one pre-eminently calculated to develop results of importance 

 in Physiology : and is the only one out of which definite indications in regard to the 

 Therapeutic applications of Electricity can be expected to arise. 



1 " Casper's Wochenschrift," 1849, No. 15. 



2 "American Journal of Medical Sciences," January, 1838. 



