4G0 M. Haagen on the Refractive Indices of seme Haloid Compounds. 

 II. Bromine, calculated from G 2 H 5 Br . 14-96 14-40 



CH»Br 



. 15-68 



15-07 



€*H< Br'< 



-, 15-39 



14-78 



Mean . . 



. 15-34 



14-75 





±0-36 



±0-34 



III. Iodine, calculated from . € H 3 1 



. 23-99 



22-69 



€ 2 H*I 



. 24-46 



23-10 



^H»I 



. 26-16 



24-85 



Mean . . 



. 24-87 



23-55 





±1-08 



+ 1-08 



IV. Sulphur, taking Cl a = 9* 79,1 pg 2 

 calculated from . . J 



. 16-03 



14-74 



g 2 CP . 



. 16-03 





V. Phosphorus, calculated from PCI 3 . 



. 14-93 



14-60 



VI. Arsenic „ „ As CI 3 . 



. 20-22 



18-84 



VII. Antimony „ „ Sb CI 5 . 



. 25-66 





VIII. Tin „ „ SnCi 4 



. 1989 



18-64 



IX. Silicon „ „ Si CI 4 



. 7-90 



7-81 



X. Sodium ,, „ NaCl 



. 4-89 



4-71 



The author gives in the following Table the refractive equi- 

 valent which he has obtained, and the values for the specific re- 

 fractive power obtained by dividing the refractive equivalents by 

 the atomic weights. He gives at the same time SchrauPs re- 

 fractive equivalents, which that physicist calculated from trust- 

 worthy observations by various experimenters : — 





P. 



p Pa—I 



d 



pA-1 



d 



f&a— 1 



d 



A-l 



d 



Schrauf's 

 refractive 

 equivalent. 



Hydrogen 



Chlorine 



1 



35-5 



80 

 127 



16 



32 



31 



75 

 122 



12 



28 

 118 



23 



1-30 



9-79 



15-34 



24-87 



3-00 



1603 



14-93 



20-22 



2566 



5-00 



7-90 



19-89 



4-89 



1-29 



9-53 



14-75 



23-55 



2-90 



14-74 



14-60 



18-84 



"i'-Oe 



7-81 



18-64 



4-71 



1-3000 

 0-2758 

 0-1918 

 0-1958 

 0-1875 

 0-5009 

 0-4816 

 0-2696 

 0-2103 

 0-4167 

 0-2821 

 1686 

 02126 



1-2900 

 0-2685 

 0-1844 

 0-1854 

 01813 

 0-4606 

 04710 

 0-2512 



0-4050 

 0-2789 

 0-1580 

 0-2048 



1*57 



8-58 

 13-85 

 2310 



3-03 

 16-32 

 18-81 

 14-45 



4-85 



6-27 



23-47 



4-54 



Bromine 





Oxygen 



Sulphur 



Phosphorus ... 

 Arsenic 



Antimony 



Carbon 





Tin.... 



Sodium 









There is thus seen to be a sufficiently close agreement between 

 the values for the refractive equivalents of those elements which 

 couldbe calculated from observations in the free state, andthevalues 



