WILLIAM GILBERT. 55 



The first chapter of Book I. is devoted to a review of the older 

 writers and their various opinions and vanities, which he scornfully 

 dismisses by remarking that only plebeian philosophers delight them- 

 selves in such nonsense, and names the following as the men who 

 have really added to magnetic knowledge : Thomas Hariot, Robert 

 Hues, Edward Wright, Abraham Kendall, William Borough, William 

 Barlowe, and Robert Norman — all Englishmen. 



In the second chapter he enters upon a learned discussion as to 

 the etymology of the word magnet, the origin of its discovery in 

 prehistoric times, and the localities whence the loadstone is procured. 

 In the third chapter begins the experimental method. The proposition 

 that a magnet possesses certain parts, or poles, distinguished by their 

 natural power is established by experiment ; a loadstone ground down 

 on a lapidary's wheel to a spherical shape being the form preferred, 

 as being geometrically the most perfect and as being fittest for experi- 

 ments as resembling the globe of the earth. Such a globular load- 

 stone Gilbert called a "Terrella." To the pole pointing southwards 

 Gilbert assigned the name " boreal " on account of the law of 

 attraction between opposite kinds of poles, arguing that the polarity 

 of the pole which pointed southwards must be a pole of the opposite 

 kind. This led to further experiments on loadstones, which were cut 

 into two parts, the parts being floated on water in little vessels. 

 Subsequent chapters deal with the attraction of the loadstone for iron, 

 and with the properties of iron as contrasted with those of other 

 metals ; many a passing hit at the absurdities of astrologists and 

 alchemists being interposed. He then shows that iron which has not 

 been touched by any loadstone can nevertheless act magnetically on 

 other iron. To show this a light piece of iron wire is thrust through 

 a small ball of cork and set to float, and toward it is brought the 

 lower end of a long iron rod held above it. The one turns toward 

 the other. Another experimental discovery is that a long iron rod, 

 delicately hung by a special silk thread, will turn, even though not 

 previously magnetised by contact with any magnet, and place itself in 

 the direction of the compass. In chapters fourteen and fifteen is 

 interpolated a description of the alleged medicinal powers of the 

 magnet, beginning with its use, as prescribed by Dioscorides and 

 Galen, to drive away melancholy, and ending with Paracelsus who 

 recommended poultices containing powdered magnets. Short shrift 

 would modern magnetopathic quacks have got, with their magnetic 

 belts and rings, at the hands of the outspoken doctor. After a short 



