6 ESSAYS BIOGRAPHICAL AND CHEMICAL 



constituents of the alphabet, so an ' element ' was regarded 

 as a constituent of substances. From the use of the 

 word by ancient authors, however, it would appear that 

 an element was often regarded as a property of matter ; 

 and it was evidently supposed that by changing the 

 properties, or in the words of the old writers adding more 

 or less of one or other element to a substance, the 

 substance itself could be transmuted into another wholly 

 different. We shall see examples of the two meanings 

 illustrated later on. 



It is probable that the original ideas of elements 

 reached Greece from India. The Buddhistic teaching 

 was that the elements are six in number, namely, Earth, 

 Water, Air, Fire, Ether, and Consciousness. But they are 

 given by Empedocles of Agrigent, who lived about 440 

 B.C., without, the two last; and many disputes arose as 

 to which was to be regarded as the primary one, from 

 which all the others were derived ; for even at that 

 remote date, speculation was rife as to the unity of 

 matter. While Thales contended that the original 

 element was water, Anaximenes believed it to be air or 

 fire; and Aristotle did not regard elements as different 

 kinds of matter, but as different properties appertaining 

 to one original matter. Plato, however, evidently con- 

 sidered elements to be different kinds of matter, for he 

 puts these words into the mouth of Timaeus : 'In the 

 first place, that which we are now calling water, when 

 congealed, becomes stone and earth, as our sight seems 

 to show us [here he refers probably to rock-crystal, then 

 supposed to be petrified ice] ; and this same element, 

 when melted and dispersed, passes into vapour and fire. 

 Air, again, when burnt up, becomes fire, and again fire, 

 when condensed and extinguished, passes once more 

 into the form of air ; and once more air, when collected 

 and condensed, produces cloud and vapour; and from 



