THE DEVELOPMENT OF ELECTRICAL SCIENCE. 1 



By Thomas Cray. 



In a brief discourse on the development of electrical science little 

 time can be given to the early history of the subject. This part is 

 more or less familiar to all the members of the academy, and hence it 

 may be passed over by only such brief reference as may serve to recall 

 to mind the more important of the early discoveries. The early Greeks 

 have recorded some elementary phenomena now known to be electric, 

 and it is probable that such knowledge was not uncommon, though 

 little noticed. It is only in comparatively recent times that scientific 

 research has taken the place of superstition and attempts have been 

 made to classify and find reasons for the existence of all natural phe- 

 nomena. 



Beginning - with the seventeenth century, probably the first investi- 

 gator worthy of notice in this subject was Gilbert, of Colchester, who 

 published his work entitled De Magnete in 1600. Gilbert made sys- 

 tematic experiments and showed that the property of attracting light 

 bodies could be given to a large number of substances by friction. He 

 also showed that the success of the experiment depended largely upon 

 the dryness of the body. These experiments gave rise to the classifi- 

 cation of substances as electrics and nonelectrics. The true signifi- 

 cance of Gilbert's observations as to the effect of moisture was not 

 appreciated for a long time. Gilbert's list of electrics was added to by 

 a number of other observers, prominent among whom were Boyle and 

 Newton. The fact that light and sound accompany electric excitation 

 was called attention to by Otto von Guericke, who also showed that a 

 light body after being brought into contact with an electrified body was 

 repelled by it. 



Coining now to the eighteenth century, we find Hawkesbee in 1707 

 and Wall in 1708 speculating on the similarity of the electric spark 

 and lightning. Then comes one of the most prominent experimenters 

 of this century — Stephen Gray — who began to publish in 1720, and 

 who in 1729 found that certain substances would not convey the charge 



'Address of the president delivered before the annual meeting of the Indiana 

 Academy of Sciences on December 29, 1897. Printed in Science March 18 and 25, 

 1898. 



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