STANISLAO CANNIZZARO 151 



combination. ... In reference to the existence of bodies com- 

 posed of the same elements, and in the same proportions, but 

 differing in their quahties, it may be observed, that now we 

 are taught to look for them, they will probably multiply upon 

 us." 



Faraday's expectation has been overwhelmingly realised. 



In 1830 Berzelius constructed the adjective isomeric, and 

 applied it to compounds which have the same composition but 

 not identical properties. The isolation of many isomeric com- 

 pounds seemed only to make chemical confusion worse con- 

 founded. 



A question concerning the elements propounded by Berzelius 

 in his memoir of 1830 widened the chemical horizon, and, while 

 deepening the perplexities, also increased the zeal of chemical 

 investigators. Berzelius recited facts which seemed to show 

 that some elements exhibit a phenomenon similar to isomerism 

 of compounds. To obtain some clear conception of the 

 isomerism of compounds and the allotropy of elements, Berzelius 

 suggested that the differences between isomeric compounds may 

 be associated with differences of aggregation of their minute 

 particles, and the differences between the allotropic forms of an 

 element, with changes in the arrangement of the atoms of the 

 element. 



When Cannizzaro was six years old, Wohler and Liebig 

 published their research on oil of bitter almonds. Trying to 

 bring into one point of view the many interactions and re- 

 lations of the compounds they had isolated and studied, the two 

 chemists introduced into organic chemistry the notion of " the 

 compounded element," named also the compound radicle. They 

 thought of the collocation of certain quantities by weight of the 

 three elements, carbon hydrogen and oxygen, as a group of 

 atoms of comparatively great stability, which acted in many 

 chemical transformations in the same way as an element acts, 

 that is, combined as a whole with other elements and separated 

 as a whole from its combinations with other elements. They 

 thought of this hypothetical compounded element, which they 

 named benzoyl, as a " foundation " whereon many compounds 

 were built, and they associated the observed similarities between 

 these compounds with the assumption that they all rested on 

 one and the same foundation. Berzelius rejoiced when he 

 received a copy of their memoir from Wohler and Liebig. He 



