4 THE ELECTRIC TELEGRAPH. 



air, which he attributed to the vapours and effluvia suspended 

 in it, had determined on an experiment by which he sought 

 to preserve some of the mysterious fluid, to keep it out of 

 contact with the air. For this purpose he selected water as 

 the recipient of the fluid, and a glass bottle as the best 

 means of imprisoning it. On one occasion, happening to 

 hold the bottle in his right hand, whilst he was charging 

 the water contained in it by a wire leading to the prime 

 conductor of a very powerful electrical machine, Muschen- 

 broeck removed the wire with his left hand, and received a 

 shock which his imagination probably led him to regard as 

 much more terrible than it really was ; for, in a conversa- 

 tion with Reaumur, he is reported to have said that he felt 

 himself struck in his arms, shoulders, and breast, so that 

 he lost his breath, and was two days before he recovered 

 from the effects of the blow and the terror. " For the whole 

 kingdom of France," added Muschenbroeck, "I would not 

 take a second shock." 



9. The Leyden jar such was the name given to it thence- 

 forth was soon endowed with a more convenient form and 



Fig. i. 



became one of the chief instruments in the hands of the 

 students of electricity. 



The form given to it by Watson resembled that shown in 

 Fig. 1, in which a a is a coating of tinfoil upon the outer 

 surface of a glass jar, b b an inner coating of the same 

 material, and c a knob attached to a wire in connection with 

 the inner coating. On charging the knob and inner coating 



