66 DISSERTATION SECOND. [item. 



ble life, came now to be known, not indeed in its essence, 

 but as to all the characters in which we are practically or 

 experimentally concerned. The treatise on Fire, in Boer- 

 haave's Chemistry, is a great advance beyond any thing on 

 that subject hitherto known, and touches, notwithstanding 

 many errors and imperfections, on most of the great truths, 

 which time,, experience, and ingenuity, have since brought 

 into view. 



It was in this period also, that electricity may be said 

 first to have taken a scientific form. The power of amber 

 to attract small bodies, after it has been rubbed, is said to 

 have been known to Thales, and is certainly made men- 

 tion of by Theophrastus. The observations of Gilbert, a 

 physician of Colchester, in the end of the sixteenth cen- 

 tury, though at the distance of two thousand years, made 

 the first addition to the transient and superficial remarks 

 of the Greek naturalist, and afford a pretty full enumera- 

 tion of the bodies which can be rendered electrical by 

 friction. The Academia del Cimento, Boyle, and Otto 

 Guericke, followed in the same course ; and the latter is 

 the first who mentions the crackling noise and faint light 

 which electricity sometimes produced. These, however, 

 were hardly perceived, and it was by Dr. Wall, as de- 

 scribed in the Philosophical Transactions, that they were 

 first distinctly observed. 1 By a singularly fortunate anti- 

 cipation, he remarks of the light and crackling, that they 

 seemed in some degree to represent thunder and light- 

 ning. 



After the experiments of Hauksbee in 1709, by which 

 the knowledge of this mysterious substance was considera- 

 bly advanced, Wheeler and Gray, who had discovered that 



1 Wall's paper is in Hie Transactions for 1703, Vol. XXVI. 

 No. 314, p. 69. — Hauksbee on Electrical Light, iu the same vol- 

 ume. See Abridgment, Vol. V. p. 4U8, 411. 



