JEROME CARDAN 297 



Sambo of Ravenna and others. 1 He worked hard no 

 doubt, but as a rule mere labour inflicts no heavier 

 penalty than healthy fatigue. The destroyer of vital 

 power and spring is hard work, combined with that un- 

 sleeping diligence which must be exercised when a man 

 sets himself to undertake something more complex than 

 the mere accumulation of data, when he is forced to 

 keep his mental powers on the strain through long 

 hours of selection and co-ordination, and to fix and con- 

 centrate his energies upon the task of compelling into 

 symmetry the heap of materials lying under his hand. 

 The De Subtilitate and the De Varietate are standing 

 proofs that Cardan did not overstrain his powers by 

 exertion of this kind. 



Leaving out of the reckoning his mathematical 

 treatises, the vogue enjoyed by Cardan's published 

 works must have been a short one. They came to the 

 birth only to be buried in the yawning graves which 

 lie open in every library. At the time when Spon 

 brought out his great edition in ten folio volumes in 

 1663, the mists of oblivion must have been gathering 

 around the author's fame, and in a brief space his words 

 ceased to have any weight in the teaching of that Art he 

 had cultivated with so great zeal and affection. The 

 mathematician who talked about " Cardan's rule " to his 

 pupils was most likely ignorant both of his century and 

 his birthplace. Had it not been for the references made 

 by writers like Burton to his dabblings in occult learning, 

 his claims to read the stars, and to the guidance of a 



1 Opera,ton\. i. p. 113. On the same page he adds: " Fui autem 

 tarn felix in cito absoluendo, quam infelicissimus in sero incho 

 ando. Ccepi enim ilium anno aetatis meae quinquagesimo octavo, 

 . absolvi intra septem dies ; pene prodigio similis." 



