the Unit-Stere Theory. 



339 



In the following table the volumes o£ most of the paraffin 



series up to C 16 H 34 are 



Many of the determinations 



are those of Bartoli & Stracciati (Beibldtter zu den AnnaJen 

 der Physik und Cheniie, ix. p. 697), and are given for what 

 they are worth, for though the determinations themselves are 

 probably fairly accurate, the substances examined appear to 

 have been the isomers of the normal paraffins or admixtures 

 thereof. They were obtained by means of the fractional 

 distillation of petroleum. 



XIII.— Table of Values of V/W of the Paraffins 

 at the B.P. 



No. 



Hydrocarbon. 



B.P. 



W. 



V. 



V/W. 



Author. 



1. 



Methane, CH 4 



-164 



8 



38-6 



4-82 



Olszewski. 



2. 



Propane, C 3 H 8 



-25 



20 



70-0 



3-50 



Lefevre. 



3. 



Butane, C 4 H 10 



-1 



26 



93 



3-58 



" 



4. 



Hexane, C G H l4 



, 



68 



38 



1356 



3-57 



B. &S. 



D. 



Nonane, C q H 20 



136-8 



56 



197-1 



3-52 



tt 



6. 



Decane, C 10 H 2o 



158-62 



62 



2202 



3-55 



>> 



7. 



TJndecane, C 11 H o4 



180-2 



68 



241-9 



3-56 



,, 



8. 



Dodecane, C 10 H 26 



198-200 



74 



263-9 



3-56 



,, 



9. 



Tridecane. C 13 H 28 



218-20 



80 



284-4 



355 



t 



10. 



Tetradecane, C l4 H 30 



236-40 



86 



308-8 



3-59 



>> 



11. 



Pentadecane, C 15 ff 32 



258-62 



92 



333-0 



3-60 



,, 



12. 



Hexadecane, C lfi H 34 



278-82 



98 



353-3 



3-60 



" 



The above table shows that V/W for methane is quite 

 discordant with the rest of the series. This fact is, however, 

 not of great significance, since the boiling-point of methane 

 is hardly likely to be even an approximately corresponding 

 temperature. 



The concordance of the ratios derived from Bartoli & 

 Stracciati's determinations is somewhat remarkable. This 

 fact seems to be in favour of the view that the liquids were 

 definite isomers of the normal compounds. In any case, 

 the lower boiling-points and the smaller volumes of these 

 compounds are interesting, since they indicate that the 

 branched-chain type of structure depresses both the boiling- 

 points and the molecular volumes of the compounds. This 

 has been shown to be the case for iso-pentane, diisopropyl, and 

 diisobutyl by Young (Joe, cit.). 



