35 
PRESIDENT’S ADDRESS. 
THe DEVELOPMENT OF ELECTRICAL SCIENCE. 
By THomaAs GRaAy. 
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 onty 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 he 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 phenomena. 
Beginning with the seventeenth century, probably the first investigator 
worthy of notice in this subject was Gilbert of Colchester, who published 
his work entitled “De Magnete” in 1600. Gilbert made systematic experi- 
ments 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 classification of substances as 
electrics and non-electrics. The true effect 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 was Boyle and Newton. The fact that light and sound ac- 
companies electric excitation was called attention to by Otto Von Gue- 
ricke, who also showed that a light body, after being brought into contact 
with an electrified body, was repelled by it. ‘ 
Coming now to the eighteenth century, we find Hawkesbee in 1707, and 
Wall in 1708, speculating on the similarity of the electric spark and light- 
ning. Then comes one of the most prominent experimenters of this cen- 
tury—Stephen Gray—who began to publish in 1720, and who in 1729 found 
that certain substances would, and others would not, convey the charge 
of an electrified body to a distance. These experiments were the first to 
introduce the distinction between conductors and non-conductors, and, of 
