238 HISTORY OF CHEMISTRY. [LECTURE XII. 



them, but must also behave differently from them in many 

 essential points." 



These new substances can also be obtained from carbonic 

 acid or the fatty acids by substitution. 



We have : 



2 HO (C./X), O, Carbonic acid, 



HO CgHg (C" 2 O 2 ) O Acetic 



H 1 r 1 n Alcohol with one hydrogen atom substi- 

 (C 2 H 8 ) 2 / tuted by methyl (dimethyl-carbinol), 



HO (C H 3 ) 3 C.,, O Alcohol with two hydrogen atoms substi- 

 tuted by methyl (trimethyl-carbinol). 



Kolbe goes so far as to prophesy the chemical character of 

 these hypothetical substances. Thus, according to him, alcohol 

 with one hydrogen atom substituted by methyl must yield 

 acetone on oxidation, by virtue of a reaction which is analogous 

 to the conversion of the normal alcohols into aldehydes : 



HO C -H 3 }c,, O gives ^^JCA Aldehyde, 

 (~* T~T "I 



HO C!HJ -C,, S ives r 2 S 3 ) c -" Acetone. 

 - H J ^2J 



All these conjectures have been justified in the most brilliant 

 manner, and consequently they have exercised a guiding influ- 

 ence upon the development of the considerations regarding 

 constitution. For this reason, I must return to them in the 

 next lecture. 



Kolbe now admits the existence of polybasic acids. Dibasic 

 acids are produced, according to him, from two "atoms" of 

 carbonic acid by the replacement of two oxygen atoms outside 

 the radical (and therefore of twice O.,H) by bivalent radicals 

 such as ethylene, phenylene, etc. 54 thus : 



Succinic acid 2 HO (C 4 H 4 ) f *^ j-O 2 

 Phthalic 2 HO (CuHijI&S^Oy 



^2^2^ 



54 The idea of polyatomic alcohol radicals is not due to Kolbe, but to 

 Williamson and Wurtz, as the accompanying development of the subject 

 shows. 



