326 Mr. W. Hibbert on the Gladstone 



4 the indices for the line a. Col. 5 gives three values of 

 /3 as calculated from the two indices for each of the lines 

 a, D, and j8. The indices for D and /3 will be found in the 

 original paper. 



Table I. 



Substance. 



Temp. 



Density. 



/*«• 



0= 



(/x-l>-(// 1 -l)y ] 



V 



at lower 

 te-np. 



V 



Thymol, O 10 H u O. 



Cirmamic Alcohol, 

 C 9 H 10 O. 



Anethol, C 10 H ]2 O. 



a- Methyl a-Naphthol, 

 C n H io°- 



Dimethylnaphthalene, 

 O ia H 12 . 



o 



24 

 77-3 



24-8 

 773 



14-9 



77 



14 



77 



16-4 



77 



0-96895 

 0-92838 



104017 

 1-00027 



0-99132 

 0-94041 



1-09636 

 104661 



101803 

 0-97411 



al-51453 



al-49189 



1-57311 

 1-54939 



1-55559 

 1-52526 



1-61474 



1-58508 



1-60765 

 1-57901 



00563 

 00600 

 00623 



1-0320 



0-96055 



1-0087 



0-9121 



0-9823 



0-058 



0-083 



00655 



0-0680 



009 



Mean 0-0600 



0077 

 0-086 

 0-011 



0080 



0066 

 063 

 0069 



0066 



0-0566 

 0-0570 

 0-0850 



00620 



0869 

 0-0899 

 00893 



0-0890 



The third value (that given by H/3) for cinnamic alcohol 

 appears to be wrong, and the third value for methyl a- 

 naphthol also, though to a less degree. In calculating the 

 means, I have ignored the first and allowed only half weight 

 to the second of these. 



The next table contains all the observations made by Perkin*, 

 whose apparatus was still more perfect than that of Nasini 

 and Bernheimer. The index is quoted here for the line D 

 only, but the quantity /3 has been calculated from the lines 

 A, C, D, and F. Where a fifth value is given, it is calcu- 

 lated from the line Gr. 



* Chem. Soc. Journ. 1892, pp. 287 & 800. 



