508 THE INTELLECTUAL RISE IN ELECTRICITY. 



At about the same time, 1745, appeared the proposal to 

 utilize electric light, made by Gottfried Heinrich Grum- 

 inert, of Biala, Poland, who claimed to have found that 

 a vacuum tube, after being set in glow through prox- 

 imity to a powerfully electrified conductor, could, after a 

 period of rest, be made to glow again without being re- 

 electrified probably by rubbing, as Hauksbee had done 

 the same thing. This, however, he proposed to use "in 

 mines and places where common fires and lights cannot be 

 had,'' so that, in his notion, there is the germ both of 

 electric illumination and the safety lamp. One other dis- 

 covery closes the list of all that are worth especially not- 

 ing among the many which fill the German treatises of 

 the day, and that marks the first step in electro-chemistry. 

 Kriiger learned from Hausen of the sulphurous odor of the 

 electric glow, due, as is now known, to the conversion of 

 the oxygen of the air into ozone, and recalling the bleach- 

 ing power of sulphur, determined to try whether electricity 

 could cause discharge of color. He exposed red poppy 

 leaves, and they quickly turned white ; blue and yellow 

 flowers blanched after some hours. 



While the activity of the English philosophers had not 

 been equal to that of the Germans, it had continued, 

 and Dr. William Watson, apothecary and member of the 

 Royal Society, made the first of his remarkable commu- 

 nications to that body in the spring of 1745. Watson's 

 researches of that year, while mainly devoted to repetitions 

 of the German experiments, were by no means barren of 

 interesting results. He demonstrated the importance of the 

 metallic conductor in the electrical machine in collecting 

 the discharge, and concentrating it at a point. He ignited 

 hydrogen by the electric spark (the beginning of electrical 

 gas-lighting) and fired a musket by the same means; but 

 perhaps his most important revelation for the time was 

 that spirits electrified in a metallic spoon could be fired by 

 the touch of a non-electrified person just as well as an elec- 

 trified person could in like manner ignite non-electrified 



