150 BROOM ALL : 



before the electric current was turned on. This remarkable 

 phenomenon could be reproduced several times by rubbing the 

 bulb with the hand. It should be said, however, that the 

 experiment did not succeed with all bulbs and that those that 

 had been used for sortie time and had on them the well known 

 dark deposits of carbon were apt not to show the effect. 

 When, on the contrary, the lamp was new or unused, even 

 without any metallic conductor at all, if rubbed smartly on 

 the skin, for example on the forehead or forearm, and sud- 

 denly removed, it showed tlie phenomenon described above. 

 If, after removing the lamp, it is suddenly stopped, its contour 

 is seen to be distinctly illuminated, and a bright spot is 

 observed in the middle of it. 



" When, after having rubl)ed the lamp on iionie part of the 

 body, another part is touched — the cheek, for instance — the 

 same luminosity is produced, even without further rubbing, 

 by the simple contact, lighting up part of the face. If the 

 breath strikes a lamp that has been rublied on some part of 

 the body, a well marked light is also produced. The phenom- 

 ena in question, according to Professor Sommer, are partly 

 physiological, that is to say, they belong to the human or 

 animal organism. Hut as. on the other hand, a pari of the 

 phenomena may be also pro(luce<l l)y rviiil>ing on other sub- 

 stances, they must lie gt)verne(l in jiart l>y a physical law-, 

 which presents itself in the human body under special condi- 

 tions. This luminosity may also produce photographic effects." 



The observations of Professor Sommer are the same as, or 

 at least closely related to, those of the writer, the difference 

 consisting more in the explanation than in the facts. Neither 

 theory, however, explains the phenomenon satisfactorily. 

 Thus, on the one hand, a theory attributing the light partly 

 to some physiological or other action of the skin is militated 

 against by the fact that other substances than the skin will 

 serve to excite the glow, although not so well as the bare 

 hand. Again, on the other hand, it seems difficult to recon- 



