964 
heating the formed red phosphorus, after addition of 0.4 °/, I at 
400° for 3 days, after which the said after-treatment was of course 
applied again. 
Preparation No. 4 prepared from white phosphorus by heating 
it at 550°, for 5 hours, without the addition of Todium, followed by 
the known after-treatment. 
These preparations, of which we thought ourselves justified in 
expecting that they had assumed internal equilibrium resp. at 375°, 
400°, 550° gave the following vapour pressures. 
TABLE UE 
Preparation No. 2 Preparation No. 3 | Preparation No. 4 
Temp. of preparat. 375° Temp. of preparat.410° Temp. of preparat. 550° 
Manometer No. 69 Manometer No. 72 Manometer No. 74 
Temp. Pressure Temp. Pressure | Temp. Pressure 
290° 0.05 atm. 308 .5° 0.08 atm. | 308.5° 0.07 atm. 
308.5 0.09. „ 346 Dev 346 | WAS 5 
328 | 0:15 315:5 0.40 , 379.5 035 -5 
346 Oras 394.5 Oba 408.5 061996 
365 Res EE ee 418 Ay Vd 433:5 >| “1-49, 
384.5 | 0.60 , 448.5 | 2.23 , 450.5 | 230 7% 
AAO |: (4:02 5 457.5 | 2.89 , 463.5 er 
429 rel cry 461.5 317 > Ol? eee 3:88", 
444.5 | 2.16 , 474.5 A190) 486.5 5.46, 
456 RB 
In these determinations we took care that when it seemed that 
at constant temperature also the pressure had become constant, the 
vapour pressure was observed at the same temperature for 10 or 
20 minutes more, to examine if it really did not change any more. 
When considering the result found here, which is represented 
graphically in Fig. 1, we observe that the mentioned preparations 
do not give the same vapour pressure line, but that the curve lies 
lower as the preparation is prepared at higher temperature. This 
imperfect coincidence of the three vapour pressure lines suggests 
that the establishment of the internal equilibrium in the range of 
temperature passed through here, proceeds so slowly, that no internal 
