64 SCIENCE AND IMMORTALITY 



could be transmuted. Albertus Magnus taught 

 that the birth of one element was in some way the 

 result of the corruption and death of another. 

 The great Roger Bacon taught that there was an 

 immaterial essence of matter or " yle " (a word 

 obviously derived from Aristotle's vXt]). In his 

 De Arte Chymiae he lays down the law as follows : 

 " Elementa sunt quatuor, ignis, aqua, aer, terra, 

 modi id est proprietates, sunt quatuor, calor 

 frigiditas, siccitas et humiditas, at yle est res in 

 qua non est calor nee siccitas, nee humiditas et 

 non est corpus. Et elementa sunt facta de yle et 

 unumquodque elementorum convertitur in natur- 

 am alterius element! et omnis res in quamlibet." 



Boyle, in his Sceptical Chymist^ shows that he had 

 a very shrewd conception of a prima materia. 

 " Now," he writes, " if it be true, as 'tis probable, 

 that compound bodies differ from one another in 

 nothing but various textures, resulting from the 

 magnitude, shape, motion, and arrangement of 

 their small parts, it will not be irrational to 

 conceive that one and the same particle of uni- 

 versal matter may by various alterations and 

 contextures be brought to deserve the name some- 

 times of a sulphureous (gaseous), a terrestrial, or 

 aqueous body." Geber taught that nature could 

 transmute metals, although man could not. 

 Descartes, though not an atomist, declared that " the 



