372 Prof. H. C. Plummer on the 





Table I. 







Isoparaffins : C„H 2 « + 2. 





11. 



Abs.B.P.* Calc. 



O-C. 



4. 



259-7 259-2 



+0% 



5. 



300-95 30091 



+0-04 



6. 



3350 335-0 



00 



7. 



363-3 363-8 



-0-5 



enough as far as it goes. But obviously it does not go very 

 far. The more general formula of this type, however, 



T = a\og(bn + c) 

 or its equivalent 



A.10 T,a = b, const., 



may prove more widely useful in connexion with similar 

 series. This is suggested by some experience to be described 

 later. 



As another example the small class of Irydrosulphides 

 available may be quoted. Here the simple formula 

 suggested is 



T = 30°-93(ra + 8), 



and the comparison with observation is given in Table II. 



Table II. 



Hydrosulphides : C n H 2?l+ i — SH. 



O-O. 



o 

 +0-6 



-0-3 



+0-3 



-0-7 



Again the range is too small to make any wide deduction 

 possible. 



2. Nevertheless, the linear formula, though pushed beyond 

 its legitimate limits by Kopp, certainly has its area of useful 

 application. This is to be seen in the case of the alcohols, 

 the boiling-points of which are fairly represented by the 

 formulae : 



Normal primary : T = 18*64 (rc + 17), 

 Normal secondary: 18*64 (n 4- 16), 

 Primary iso : 18*64 (n + 16*5). 



* Young, Scientific Proc. R.D.S., xv. p. 97 (1916). 



t Young, Phil. Mag. ix. p. 6 (1905) ; J. de Chimie Physique, iii. p. 245. 



n. 



Abs. B.P.t 



Calc. 



1. 



279-0 



o 

 278-4 



2. 



3090 



309-3 



3. 



340-5 



3402 



4. 



370-5 



37P2 



