J. W. Gibbs — Vapor-Densities. 871 
Bismuth. 
Time of Moment of Half Area of 
swing. inertia, length. section. 
Axis, vertical. ___. 1 oe "109768" : rin Be Soe NV 
Axis, horizontal, .. 5°76°°° "10943°8* 4208 BOTTE 
Cale-Spar. 
Time of Momentof Half Area of 
wi inerti length. section. - 
Axis, vertical .__.- 46°35°°* = -0303°8° 
‘+ r? ° ' 
xis, horizontal ... 43-39% -osoo%s. S018" "08007" 50° 80 
The linear measurements were made with a dividing engine, 
the moments of inertia were calculated from the dimensions of 
the bars. The angle at which the cale-spar stood was meas- 
ured by projecting the linear axis on a scale placed at a 
distance. 
The above quantities being all determined and properly sub- 
stituted, the solution of the equations gave for 
SOG oe ee k, =— *000 000 012 554 
| = — 000 000 014 824 
Csiowat 4522 se k, =—°000 000 037 930 
k,,=— "000 000 040 330 
Art. XLIIL—On the Vapor-Densities of Peroxide of Nitrogen, 
Formic Acid, Acetic Acid, and Perchloride of Phosphorus ; by 
ILLARD GIBBS. 
[Continued from page 293.] 
Acetic acid.—F or this substance the densities have been cal- 
culated by the formula 
2°073(D—2°073) 3520 
(F146 =D) mp o738t log p—11°349, (12) 
log 
ond column are taken from his Legons de chimie générale 
élémentaire, 1856. These numbers seem to be based in part 
* Lieb, Ann., Suppl. VI, p. 65. 
Am. Jour, Sc1.—Tamp SERizs, Vou, XVIII, No. 107.—Nov., 1879, 
24 4 
