STANISLAO CANNIZZARO 153 



proved too much for his hypothesis. He had attempted to 

 revive Avogadro's supposition, but failing to make it act as a 

 knowledge-producing instrument, he tried to convince himself 

 that his business was that of the mere fact-finder to whom 

 hypotheses are useless. Despairing of the atomic theory, in his 

 Lectures on Chemical Philosophy^ delivered in 1836, Dumas made 

 his plaint : 



" Si j'en etais le maitre, j'effacerais le mot atome de la science, 

 persuade qu'il va plus loin que I'experience ; et jamais en 

 Chemie nous ne devons aller plus loin que I'experience." 



Looking back, we see that Dumas had confused equivalent 

 weights with atomic and also with molecular weights ; none of 

 these three conceptions had been clearly grasped, and dis- 

 tinguished from the others, at the time when he promulgated his 

 notion of substitution and chemical types. 



In the forties and fifties of the nineteenth century chemistry 

 was waiting for one who should possess the condensing and 

 realising powers of a man of science, and also the generalising 

 and expanding powers of a philosopher. It was fitting that the 

 man of genius should appear in the country which had been the 

 first in Europe to break away from the deadening scholasticism 

 of the Middle Ages, to re-discover the meaning of lucid thinking 

 about realities, to welcome the return to earth of beauty, the 

 great illuminer. In 1853, Cannizzaro published his first 

 chemical memoir, on benzylic alcohol. 



From 1853 to 1855 Cannizzaro was Professor in the Technical 

 Institute of Alessandria ; for a few years he was Professor in 

 the University of Genoa ; for twelve years he was Professor 

 in his native town of Palermo. In 1871 he was called to Rome, 

 as Professor of Chemistry and member of the Italian Senate. 

 He died in Rome on May 13, 1910. 



Cannizzaro did not publish many memoirs on purely ex- 

 perimental chemistry. He was essentially a thinker. His most 

 important contributions to theoretical and philosophical chemistry 

 are contained in An Abstract of a Course of Philosophical Chem- 

 istry given in the Royal University of Genoa^ which appeared 

 in 1858; various articles in Niiovo Cimento in 1857 and 1858, 

 bearing on the fundamental conceptions of the atomic and 

 molecular theory ; and " The Faraday Lecture," delivered to the 



