LECTURE VII. J HISTORY OF CHEMISTRY. lOQ 



compounds it is a compound radical. The latter name had 

 not been lost. The chemical nomenclature had been based 

 upon it, and the dualism of Berzelius was a happy extension of 

 it. All observations seemed to be in agreement with it. Thus 

 the salts (at that time the best known class of substances) are 

 formed from acid and base, and they can be decomposed again 

 into these constituents. Why should we not endeavour to 

 look upon organic compounds also as formed in a similar way ? 

 Since organic compounds (according to the view held at that 

 period) consisted of at least three elements, any simple de- 

 composition must still leave one part of a composite nature. 

 Organic chemistry thus became the Chemistry of the Compound 

 Radicals. In thus employing the term radical, its original 

 definition was retained. After the removal of the oxygen from 

 a substance, the residue which remained, and which, moreover, 

 played the part of an element, was called a radical. Wohler 

 and Liebig remodelled this conception. In their admirable 

 research on bitter almond oil and the allied compounds, they 

 showed that we may assume the existence, in these substances, 

 of an oxygenated group which remains unchanged in the 

 majority of the reactions, and therefore behaves like an 

 elementary substance. On this account, they called it the 

 radical of bitter almond oil. 



By this departure the first great step had been taken ; 

 organic chemistry had become independent ; it had freed itself 

 from the fetters which had been placed upon it ; if, from 

 within its own limits, it had not produced a new idea, it had at 

 least given new and increased importance to one which was 

 already held. From this time forward, it proceeds on its own 

 way, and pays no heed to the limitations which some desired 

 to place upon it. The very harmonious edifice of chemistry 

 suffers in consequence. Every endeavour is made to adapt it 

 to the new ideas. But it is in vain the breach is unavoidable. 

 The young science, quite conscious of its own strength, dares 

 to make an assault upon the foundations, and, in spite of stays 

 and props, the structure begins to totter. The attack upon 

 the electro-chemical theory led to an embittered controversy 



