of some Haloid Compounds. 459 



with and H. The value thus obtained for chlorine renders it 

 possible to establish the refractive index of those elements which 

 form liquid chlorides. 



The author has ascertained the refractive equivalents not 

 merely in reference to /j, a , but also by the aid of Cauchy's for- 



j^ \ 



mula of dispersion. For this purpose the values P ^ of H, 



O, and G had first to be calculated from Landolt's observations, 



H A =l-29; 9 A = 2-90; G A =4*86. 



/*« — 1 



which gave 



The following Table gives the specific refractive capacity £^-= 



d 



} as well as the resulting refractive equivalent obtained 



by multiplication with the molecular weight P : — 







P. 



f*a— 1 



A-l 



p (*OL— .1 



P^-J. 









d 



d ' 



d * 



d ' 



Tetrachloride of carbon. . . 



CC1* 



154 



0-2871 



0-2797 



44-21 



4307 





GHC1 3 

 G^Cl 2 



119-5 



99 



0-2974 

 0-3519 



0-2895 

 0-3436 



35-54 



34-84 



34-60 

 3402 



Chloride of ethylene 



Bromide of ethyle 



G 2 H 5 Br 



109 



0-2886 



0-2805 



31-46 



30-57 





G 5 H u Br 



151 



0-3641 



0-3547 



54-98 



53-56 



Bromide of ethylene 



9 2 H 4 Br 2 



188 



0-2446 



0-2364 



45-98 



44-44 





GH 3 I 



142 



0-2316 



6-2213 



32-89 



31-42 



Iodide of ethyle 



G 2 H 5 I 



156 



0-2626 



0-2517 



40-96 



39-27 





G 5 H 11 1 



GS2 



198 

 76 



0-3306 



0-4876 



0-3199 

 0-4517 



65-46 

 37-06 



63-34 

 34-33 



Bisulphide of carbon 



Chloride of sulphur 



S 2 CI 2 



135 



0-3825 





51-64 





Terchloride of phosphorus 



PCP 



137-5 



0-3222 



Q-314I 



44-30 



4319 



Terchloride of arsenic . . . 



As CI 3 



181-5 



0-2732 



0-2613 



49-59 



4743 



Terchloride of antimony . 



SbCl 3 



299-5 



0-2491 





74-61 





Tetrachloride of tin 



SnCl 4 



260 



02271 



0-2183 



59-05 



56-76 



Tetrachloride of silicon... 



SiCP 



170 



0-2768 



0-2702 



4706 



45-93 



Chloride of sodium 



NaCl 



58-5 



0-2509 



0-2435 



14-68 



14-24 



From these numbers the refractive equivalents P^-, — =r a 



a^ i d 



and P — j— = r A of the following elements may be calculated : — 



I. Chlorine, calculated from G CI 4 



G HC1* 



G 2 H 4 C1 2 



Mean 



9-80 

 975 

 9-82 



9-79 



r A . 



9-55 

 9-48 

 9-57 



953 



+ 0-04 +0-04 



