68 Change in the Volumes and Refractive Indices of Fluids. 



Fraunhofer 

 line. 



Interference- 

 bands, 

 Y. 



Tempera- 

 ture, t° C. 



Calculated compressibility of water. 



ju a .10 6 . 



^,10 6 . 



fJic . 10 6 . 



C 



D 



E 



F ...... 



a 





 22-55 



25-72 



28-92 



31-59 



3532 



20-40 

 20-42 

 19-60 

 18-12 

 19-41 



vol. 

 44-69 



45-51 



45-43 



45-52 



44-66 



vol. 

 5012 



52-00 



51-95 



52-08 

 51-16 



vol. 

 40-60 



41-31 



41-22 



41*26 



40-40 



Directly observed, ^-{gg J5fc *$£ 



Similar measurements with different liquids for the Fraun- 

 hofer line D give the following results: — 



Liquid. 



Glycerin 



Rape-oil 



Almond-oil 



Olive-oil 



Water 



Sulphide of carbon 



Turpentine 



Rock-oil 



Alcohol 



Ether 



Interfe- 

 rence- 

 bands, 



18-17 

 46-24 

 45-42 

 4647 

 2602 

 73-89 

 66-56 

 61-07 

 61-53 

 86-96 



Temp. 



Refra 

 tive 

 index. 



20-53 



20-3 



17-0 



20-5 



20-42 



15-0 



19-7 



194 



20-18 



180 



•4689 

 •4753 

 •4720 

 •4690 

 •3330 

 •6710 

 •4712 

 •4484 

 •3616 

 •3537 



Compressibility. 



Obs. 



25-09 

 5961 

 55-19 

 63-32 

 46-14 

 62-62 

 79-14 

 74-58 

 101-41 

 142-65 



Calculated from inter- 

 f er ence-phenomen a. 



22-81 

 57-30 

 56-67 



58-34 

 46-04 

 64-88 

 77-76 

 74-96 

 100-2 

 144-83 



27*14 

 68-30 

 67-46 

 69-42 

 52-60 

 81-17 

 92-56 

 88-72 

 115-4 

 166-6 



19-60 



49.08 

 48-59 

 50-09 

 41-78 

 50-80 

 66-68 

 64-94 

 89-84 

 130-4 



With all these liquids we find agreement between the ob- 

 served values of the compressibility and those calculated from 

 the optical experiments by the aid of equation (5 a) ; whilst 

 the values calculated by means of equations (5b) and (5c) 

 show greater differences than can be accounted for as resulting 

 from experimental errors. Hence we draw the conclusion 

 that, at constant temperature and varying hydrostatic pressure, 

 the specific refraction for the liquids which I have examined, 



= constant, 



or that the decimals of the refractive index are proportional to 

 the density. 



* Ann. de Chim. [3] xxxi. p. 477 (1851). 



