126 QUESTIONS ON THE 



330. At what time might Electricity have been first 

 properly deemed a science ? 



331. Why are certain substances termed Conductors, 

 and which are they ? 



332. Is it possible that any electric may be made to 

 become a conductor ? 



333. What is the usual mode of exciting electricity ? 



334. Are the following substances Electrics or Con- 

 ductorsglass, brass, silk, air, baked wood, water, and 

 sealing-wax ? 



335. What is Electricity ? 



336. What is the opinion of Sir Richard Phillips in 

 regard to Electricity ? 



337. What is meant by positive, and what by negative 

 electricity ? 



338. Explain the difference between vitreous and re- 

 sinous electricity. 



339. Explain the theory of Du Fay, and show in what 

 it differs from the Franklinian theory. 



340. Is it possible that different kinds of electricity 

 may be produced from the same body ? 



341 . What kind of electricity is produced from the 

 excitement of sealing-wax by fur ; and what if the seal- 

 ing-wax be excited by tinfoil ? 



342. What is the principle article in an electrical appa- 

 ratus, and describe it ? 



343. Describe the Leyden Jar. 



344. According to the Franklinian theory, what differ- 

 ence is there in the quantity of electricity that a jar may 

 contain, when charged, and when not charged ? 



345. By what means is an electric jar discharged, 

 and what is the result ? 



346. What causes that peculiar sensation called an 

 electric shock ? 



347. Why would a person not receive a shock, if he 

 were to discharge a jar by means of points ? 



348. What is meant by an electrical battery, and what 

 may be the result produced from one strongly charged ? 



349. If a jar be charged negatively, why will it give a 

 shock in a manner similar to what it would if charged 

 positively ? 



