THE LEYDEN JAR. 519 



zine, the Gentleman's Magazine, even the Newcastle Jour- 

 nal and the Caledonian Mercury, and perhaps dozens of 

 other public prints in England, were giving the new elec- 

 trical discoveries as part of the regular news of the day, as 

 fast as they were told by those who made them ; but jour- 

 nalistic enterprise of that sort had not yet reached the Con- 

 tinent, and for quick intelligence the private letter was 

 still the best and safest medium. 



In January, 1746 (the Dantzic philosophers still puzzling 

 over Von Kleist's instructions), Musschenbroeck wrote to 

 Reaumur as follows: 1 



"I wish to inform you of a new, but terrible experiment, 

 which I advise you on no account personally to attempt. 

 I am engaged in a research to determine the strength of 

 electricity. With this object I had suspended by two blue 

 silk threads, 2 a gun barrel, which received electricity by 

 communication from a glass globe which was turned 

 rapidly on its axis by one operator, while another pressed 

 his hands against it. From the opposite end of the gun 

 barrel hung a brass wire, the end of which entered a glass 

 jar, which was partly full of water. This jar I held in my 

 right hand, while with my left I attempted to draw sparks 

 from the gun barrel. Suddenly I received in my right 

 hand a shock of such violence that my whole body was 

 shaken as by* a lightning stroke. The vessel, although of 

 glass, was not broken, nor was the hand displaced by the 

 commotion: but the arm and body were affected in a man- 

 ner more terrible than I can express. In a word, I believed 

 that I was done for." 



He then proceeds to say that the shape of the vessel is 

 unimportant, but that he believes that a thin white glass 

 five inches in diameter would possibly give a shock strong 

 enough to kill. The person receiving the discharge may 



1 Memoire de 1' Acad. Roy. des Sciences, 1746, Paris. 



2 Gordon imagined that he discovered that blue silk threads insulated 

 better than any others, and for this reason every one about this time was 

 using them. 



