4 Dr. S. Young on the. Boiling- Points 



difference between calculated and observed values +2 0, 7) 

 the later ones are rather low in nearly every case. 



Table II. 



E. 



T° abs. 



A. 



T° abs. 



A. 



Obs. 



Calc. 



Diff. | 



Obs. 



Calc. 



Diff. 



RC1. 



RBr. 



CR^ ... 

 C 2 H 5 ... 

 C 3 H 7 ... 

 C 4 H 9 ... 

 5 H U ... 

 C 6 H 13 ... 



C s H n ... 



249S 

 285-5 

 319-0 

 351-0 

 3796 

 406-0 

 433-0 

 4570 



o 

 36-2 

 33-5 

 32-0 

 28-6 

 26-4 

 27-0 

 24-0 



39-85 

 35-25 

 31-55 

 28-55 

 2615 

 24-15 

 22-4 



+3-65 

 +1-75 

 -0-45 

 -0-05 

 -0 25 

 -2-85 

 -1-6 



o 

 277-5 



311-4 

 343-8 

 3740 

 402-5 

 429-0 

 452-0 

 474-0 



33% 



324 , 



30-2 



28-5 



26-5 



230 



22-0 



o 

 30-2 

 32-35 

 29-15 

 26-6 

 24-45 

 22-6 

 21-15 



o 

 +2-3 | 

 -0-05 

 -1-05 

 -1-9 

 -2-05 

 -0-4 1 

 -0-85 



RI. 





CR, ... 



CJR-o ■■■ 

 C 3 H 7 ... 

 0,H 9 ... 

 C 5 H U ... 

 C 6 H 13 ... 



315-8 

 345-5 

 375-5 

 403 

 429-0 

 452-0 



29-7 

 30-0 

 27-5 

 260 

 23-0 



31-85 



29-0 



26-5 



24-4 



22-6 



o 



+2-15 



-1-0 



-10 



-1-6 



-0-4 









i 



Somewhat similar results are in general obtained with 

 other homologous series of compounds in which molecular 

 association is not believed to occur; for example, with other 

 hydrocarbons, with the ethers, aldehydes, amines, and hydro- 

 sulphides. In the great majority of cases the deviations are 

 greatest for the lowest members of a series, and this may 

 perhaps be explained in the manner suggested by Ramage. 

 Each series, therefore, is divided into two groups; the first 

 ending and the second beginning with the lowest member of 

 the series that contains a CH 2 group linked to two carbon 

 atoms. Thus, of the alkyl chlorides, the first group contains 

 CH 3 01, CH 3 — CH 2 C1, and CH 3 — CH 2 — CH 2 Cl,and the second 

 group begins with propyl chloride, so that all its members 

 contain one or more C — CH 2 — C groups. 



In the case of the ethers, esters, and other compounds 

 which contain two alkyl groups, a series is regarded as 

 homologous when one radical remains unaltered and the 

 other increases by stages of CH 2 . The variable radical only 

 is considered in dividing the series into the two groups ; 

 thus, although propionic acid contains a C — CH 2 — C group, 

 it remains unchanged in the propionic esters, the first group 



