( 924 ) 
which may be obtained in a very large quantity, and its subsequent 
decrease, were to be ascertained with exceeding clearness. This may 
be in connection with the fact that in this case the p,v-loop is very 
steep and very narrow, so that comparatively high above the plait- 
point still a very great quantity of liquid is to be found. At any 
rate these phenomena prove again, how enormous an influence 
a small quantity of admixture may have on the behaviour of a 
substance. A quantity of not quite O.4°/, admixture first gives three- 
phase-pressure, then a very pronounced retrograde condensation, and 
thus modifies the phenomena of condensation of the pure carbonic 
acid altogether. 
THREE-PHASE-PRESSURES OF THE SYSTEM URETHANE-CARBONIC ACID. 
(The Roman figures denote with which of the above-mentioned 
mixtures the determination was made). 
a PE oe feos Mixture. yen kale ze a enen Sattdre 
26-1 65 15 I 34.5 78.30 Vv 
98:9 | 69.55 IV 34.9 79.10 VI 
(29.7) 70.35) V 34.9 79.15 Ill 
(31.6) (73.35) Mie: MP 79.85 Vv 
31.7 73.85 Vv 35.8 80.65 lll 
31.8 74.05 Vv | 35.85 80.80 VI 
31.9 74.20 Ill 36.4 | 81.20 VI 
32.05 74.35 I 36.6 | 82.30 Il 
(32.05) (74.20) | lll 37.4 82.80 Il 
32.4 75.00 | V Ses), Sl Il Maximum 
33.0 75.70 Ill 
33.4 76.30 V 
33.95 77.35 UI 
Amsterdam. Physical Laboratory of the University. 
(May 24, 1909). 
Proceedings Royal Acad. Amsterdam. Vol. XL. 
