306 THE INTELLECTUAL RISE IN ELECTRICITY. 



here is a man at the end of the sixteenth century under- 

 taking the study of a natural occurrence which had never 

 before been systematically studied at all, and which no 

 one understood. 



How did he set to work? The ordinary course of pro- 

 cedure of the contemporary philosopher would be the 

 gathering of a few isolated examples, not necessarily cor- 

 related, although ostensibly applicable to the same subject, 

 and the making of a speculation or several speculations of 

 more or less ingenuity about them. Nothing could differ 

 more widely from this than the strikingly original course 

 now followed by Gilbert. Despite the overwhelming au- 

 thority of Galen and Avicenna, he brushes aside their 

 guesses at the causes of attraction, as w 7 holly inadequate 

 to explain, and then, for the first time in the history of 

 modern philosophical thought, he systematically gathers 

 negative instances and undertakes affirmatively to discover 

 and separate out the truth by proper rejections and exclu- 

 sions something which "had not been done or even at- 

 tempted," says Bacon, u except perhaps by Plato." 



The attraction of electrics he finds is not caused : 



By heat, because heating alone, even up to the flaming 

 point, will not produce it. 



By a mode of operation analogous to that of the cupping 

 glass, as Cardan suggests, because of the contradictory 

 character of Cardan's own explanations, which we have 

 already noted. 



By the seeking of other bodies by the electric as food, 

 because the attracted body would then diminish while the 

 electric would grow. 



By the attractive force of fire, because the non-electrics, 

 when heated by fire or the sun, show no attraction. 



By draught of displaced air (the cause assigned by Lu- 

 cretius to magnetic movements), because that effect could 

 not produce attraction in the open atmosphere. 



By hot objects or by a draught of hot air, for neither an 

 iron rod at white heat nor a candle-flame brought near the 



