184 



Dr. A. Schrauf on certain Objections to the 



of these formula? (I.) and (VI.) is better in accord with the facts, 

 I sought to compare widely different modifications of the ele- 

 ments, since we may presume that these are subject to much less 

 variations than complicated combinations. 



Calculation gives: — 



Carbon . 

 Sulphur . 

 Phosphorus 

 Arsenic . 



{Diamond 

 Anthracite 



{ 



Vapour 

 Solid . 



{Vapour 

 Solid . 



J" Vapour 

 V Solid . 



0-001820 

 0-001829 



0-000492 

 0-002017 

 0-000626 

 0-002437 



0-000217 

 0-000650 



u-1 



0-000529 

 0-000664 



0000246 

 0-000659 



0000313 

 0-000784 



000108 

 0000247 



The comparison of these numbers leads us to maintain the 

 Newtonian refractive power M, since the latter are either equal 

 or simple multiples. In the Biotas formula m no such uncon- 

 strained agreement can be seen. Even the law of simple factors 

 is here of no avail, although it is evident that undetermined 

 factors are also necessary for m. 



The law of simple factors, however, is a universally valid one 

 for all physical properties of the elements ; for the consideration 

 of the atomic volumes, specific heats, &c. always leads us to the 

 distinct proposition, "The functional values of analogous ele- 

 ments are either equal or simple multiples of one another." 



Apart from the above examples, the values of the Newtonian 

 refractive powers [(/^ 2 — 1)V] for the elements show in the clear- 

 est manner the law of the homologous series. 



In the following Table these values are given side by side with 

 their factors : — 



M--1 ™ m 2 -1 ™ 





D m ' 







D iV1 ' 





. 



Se . 



. =0-000489 



. =0-000492 



. =0-001589 



= 0002016 



• (I) 



• (1) 

 . (3) 



• (4) 



As, • 



N . 



P. 



ASy 



= 0-000216 . 

 = 0000596 . 

 = 0-000602 . 

 = 0000641 . 



(1) 

 (3) 

 (3) 

 (3) 



Al . 

 Zr . 

 Be . 



. =0-000846 



. =0-000854 



= 0-001640 



• (1) 



• (1) 

 . (2) 



Sn 



Si 



Ti 



= 0-000652 . 



= 0-001247 . 



. =0-002520 . 



(1) 

 (2) 

 (4) 



Tl . 

 Ka . 



Na . 

 Li . . 



= 0-000324 

 . =0000483 

 . =0-000670 



= 0-001646 



. (2) 

 . (3) 



• W 

 . (10) 



Ba 

 Pb 



Ca . 

 Mg 



= 0-000332 . 



= 0-000479 . 



= 0-000664 . 



. =0-001290 . 



(2) 



(3) 

 (4) 



(8) 



