Affinity and Dissected {Structural) Formulae, 



423 



- Palmitic acid and cetyl palmitate also accord with the rule in 

 the same way, since the latter has an affinity- value 242-7-2043, 

 or +38-3 higher than that of the former, whilst its boiling-point 

 is also higher, though how much is unknown. 



If the uncorrected affinity- values for ethyl butyrate and amyl 

 acetate be taken, these substances would form apparent excep- 

 tions to the above rule, the affinity-value differences being then 

 + 1-4 and —13*3 instead of — 36*3 and +4'4 respectively. 

 Methyl butyrate and valerate and ethyl formate agree with the 

 rule whichever values be taken. 



35. Again, in the case of alcohols and ethers, the rule is ob- 

 served:-- 



Substance. 



Affinity-value. 



Boiling-point. 



Ethylic alcohol 



%} Diff. =-307 



mi] Diff - =- 20 ' 4 



§g*j.Di<r.~M 



mi Diff =+19 ' 8 



11} Diff. = +30-1 



J 



I 8 -} Diff. =-■ 43 



si} Diff. =-30 

 11} Di « ~+ 48 

 18o} Diff - =+ 102 

 180 } Diff - =+ ,,S 



Ethylic ether 



Methylic alcohol 



Ethylic ether 



Amylic alcohol 



Amylic ether 



Ethylic alcohol 



Amylic ether 



Methylic alcohol 



Amvlic ether 





. There is one apparent exception to the generality of the rule, 

 viz. amylic alcohol and ether. Concerning this case and certain 

 others where the rule only holds with some limitation, vide § 37; 

 it is, however, clearly noticeable that the direction of the boiling- 

 point alterations is all the way through the series the same as 

 that of the affinity- value differences; i. e. in each series each 

 difference is obtainable from the previous one by the addition 

 thereto of a positive quantity. 



. 36. The rule holds in cases of substitution of H 2 by O ; and 

 it is noticeable that in the case of the substances water and 

 oxygen, where the affinity- value is lowered by this operation, the 

 boiling-point is also lowered; so that this apparent exception is, 

 like the case of water and methylic alcohol, only a particular 

 ease of a more general rule. 



