1877.] 



Properties of Homologues and Isomers. 



.243 



anhydride. The pure iodide thus obtained amounted to about 1100 

 grms. ; it was carefully fractioned, and after four distillations collected 

 in the following five portions : — 



A. Below 102°. "] 



I. 102°-0 to 102°-25. I m 



II. 102-25 to 102-5. ^Temperatures 

 HI. 102-5 to 102-75. | not corrected - 



B. Above 102-75. J 



The densities of L, II., and III. were as follows : — 



I. 1-74772 at 20-79 ; 1-78684 at 0. 

 n. 1-75035 at 19-27; 1*78641 at 0. 



III. 1-71623 at 20-91 ; 1-78550 at 0. 



The densities at zero are calculated by means of the curve of expan- 

 sion afterwards determined. 



For the mean density of zero we have D = 1*7863. 



The density is given by Chapman and Smith (Chem. Soc. Journ. xxii. 

 195) as 1-7343 at 16° : by Bossi (Ann. Chem. and Pharm. clix. 79) as 

 1"7S2 at 0° ; by Linnemann (Ann. Chem. und Pharm. cLd. 34) as 1-7610 

 at 16°; and by Pierre and Puchot (Ann. Chim. et Phys. (4) xxii. 286) as 

 1-7842 at 0°. 



To obtain the rate of expansion, one of the dilatometers was filled with 

 Fraction I. and another with III. The final results were as follows : — 



Fraction I. Fraction III. 



Xo. of 

 Obs. 



Temperature 

 (corrected). 



Volume. 



No. of 

 Obs. 



Temperature 

 (corrected). 



Volume. 



1 



U-0 (ice) 



1-00000 



2 



5-0 (ice) 



1-00000 



I 



7-06 



1-00745 



3 



7-08 



1-00740 





15-01 



1-01601 



3 



15-07 



1-01606 



3 



23-95 



1-02586 



3 



23-99 



1-02593 



3 



30-99 



1-03383 



3 



31-00 



1-03385 



2 



39-01 



1-04312- 



4 



39-09 



1-04322 



3 



44-23 



1-04933 



3 



44-20 



1-04930 



4 



50-41 



1-05655 



o 



50-35 



1-05644 



3 



50-56 



1-05672 



3 



50-45 



1-05655 



3 



57-16 



1-06501 



3 



57-06 



1-06479 



3 



68-07 



1-07895 



3 



67-84 



1-07849 



3 



75-21 . 



1-08830 



3 



75-11 



1-03797 



3 



80-87 



1-09600 



3 



80-77 



1-09558 



3 



88-70 



1-10671 



3 



88-58 



1-10603 



5 



96-94 



1-11836 



5 



96-74 



1-11750 



The above results were marked on a large sheet of paper divided by 

 parallel lines into squares, and the points united by means of a curve ; 

 the two curves thus obtained being nearly coincident, I judged it un- 

 necessary to repeat the experiment with Fraction II. 



s2 



