Phosphorustribromide : PBr;. 
® | Maximum Pressure H | 
eu; | | Surface. | Molecular 
Bo | in mm. mer | tension xin | Han | pacar oe 
‘ - 2 | gravi o nergy in 
ES eury of | in-Dynes || Erg per cm?. | 4 2 
nS 0°°C. | : | | Erg per cm?. 
—20 | 1.939 2585.2 45.8 2.972 | 927.0 
Oi, 1.894 | 2525.0 44,7 2.923 914.8 
20.8 | 1.831 | 2441.0 43.2 2.871 894.7 
303" 1105 [Bom ee AIR 42.3 2.837 883.0 
50.3 | 1.749 | 2332 41.3 2.799 870.0 
64.8 | 1.699 | 2266.2 40.1 2.762 852.2 
derde | 1.650 2200.2 38.9 2133 | 832.1 
90 1.574 | 2098. 4 910 2.701 798.1 
99.8 « 1.526 | 2035. 2 36.0 2.676 | 781.4 
116 | 1.438 1916.9 33.8 2.635 141.0 
125 1.386 1848. 1 32.6 2.615 718.5 
140 1.295 VAA 30.4 2.911 676.6 
154 1.213 | 1617.1 28.4 2.542 637.9 
170 1.126 | 1501.7 26.3 2.502 597.0 
Radius of the Capillary tube: 0.03636 cm. 
Depth: 0.1 mm. 
Under a pressure of 750 mm. the compound boils at 170°.2 C. The bromide 
solidifies at —50° C., and melts again at —40° C. At the boilingpoint ~ has 
the value: 26.2 Erg. 
The temperature-coefficient of » increases gradually: between — 20° and 
50° it is: 0.81 Erg; between 50° and 65° C.: 1.22; between 65° and 76° C.: 
1.84; between 76° and 100°: 2.03; between 100° and 170°: 2.63 Erg ; etc. 
The specific gravities were calculated from the data given in literature by 
interpolation. 
"Molecular weight: 270.6. 
4. 
Phosphorus-Triiodide: PJ. 
Maximum Pressure H 
T EDE SE We Surface- 
pie ii ; | | tension 7 in | 
in ; in mm. mer- | 5 
cury of | in Dynes Erg. per cmf. 
ONE: | 
75.3 1.999 2665.3. | - 56.5 
90.9 | 1.962 2616.9 55.5 
105.5 1.931 | 2574.4 | 54.6 
121.4 1.898 2530.4 53.6 
135.5 1.852 | 2469.1 | 52.4 
150 | 1.817 2423 .4 ol. 
Molecular weight: 411,8. Radius of the Capillary tube: 
0.04242 cm. 
Depth: 0.1 mm. 
The red crystals melt at 55°—60° C.; the compound 
sublimes rapidly and is so easily attacked by water, that 
measurements of the specific weight are almost impossible. 
