( 634 ) 



Lord Rayt,kigh's nianometer, appeared to amount to 0.1 scale dixision 

 or to 0.()()()45 111.111. Hii'. whereas with my manometer it amounted 

 to 0.00025 111.111. Hu', as has been said before. 



Fig. 4 represents the whole arrangement. .1 is the niieromanometer, 

 B the automatic mercury air-juimp, C the manometer of Lord 

 R.VYLEIGH and I) the reading ulass with scale and mirror, c/ is a strip 

 of mirror, cul from a sphere. In the focus an incandescent lamp h 

 is placed, over which a glass cnp has l)een placed enveloped with 

 tillering i)aper. A ])arallel jtencil of rays falls through the glass scale 

 (' and is retlected Ity the mirror M from the manometer into the 

 reading glass d. 



From this tigure the connection of C with .4 through the long 

 glass tui)es c and /' is also clearly vi.sible. The results obtained by 

 this arrangement are summarized in the following tables. 



T A B L E L 



XaCl. 



r,o—P. ^ 



U,0H3i6 



I.9r. 

 l.Sl 

 1 740 

 1.742 

 1.771 

 1 S22 

 I. ''17 



With the aniline-water manometer the following results had l>een 

 before obtained. 



We see from this that the tables I and 11 harmonize very well 

 rpialitatively ; both gi\e a minimum value of / foi' the concentration 

 ± 0.5 gr. mol. 



That there are dili'ereiices in many cases in the absolute \alues of 

 / is probal)ly due to the uncertainty which exists in applying the 

 temperature correction when working with my nianometer. In future 



1) p,n = molecular diminution of vapour tension. 



2} 0,08310 = theoretical mol, diminution of vap. tens, at 0', 



