ELEMENTS ORIGIN OF SPRINGS. 61 



hard and eternal, out of which things have been created 

 according to their form and nature. In their creation 

 the Divine Being has produced, he says, the best combi- 

 nation that was possible of an existing material, eternal 

 like Himself 1 . Having discussed matter and first princi- 

 ples, cold and heat, dryness and moisture, the book passes 

 on to the description of a few mechanical contrivances of 

 a wonderful lamp, pumps, siphons, Jerome's contrivance for 

 the raising of sunk vessels, levers, scales. He teaches that 

 there are but three elements, air, earth, and water ; fire 

 he excludes, because nothing is produced out of it. He 

 treats further of fire, of lightning, of artillery, shows how 

 to know those cannons that will burst, as one burst at 

 Pavia during the All- Saints' procession, and destroyed six 

 men. He endeavours to explain why fire can be struck 

 out of a stone, why a string will not burn when it' is tied 

 round an egg, why heat breeds putridity, and so forth. 

 He treats of air, of the cause of plague, of tides, of the 

 origin of rivers; they have, he says, many sources, but the 

 chief is air converted into water. The true theory of 

 springs, as of most other processes of nature, was unknown 

 to him. Its first discoverer was Bernard Palissy. 



Of the earth, in that part of Cardan's work to which 



i Compare the statements in book i. with the dictum in book xi. 

 " Divina igitur sapientia in unoquoque fecit optimum quod ex tali 

 materia poterat excogitari." 



