1182 



By this mode of procedm-e we have actually succeeded in determining 

 some points with the glass spring manometer at higher temperatures, 

 but in the majority of the experiments the glass spring broke before 

 the recpiired temperature had been reached. This circumstance was 

 owing to this that it often happens in case of rapid heating that 

 part of the liquid white phosphorus is enclosed by a wall of red 

 phosphorus. If now the tension in the space outside has become less 

 than the tension of the enclosed liquid phosphorus, the wall of red 

 phosphorus breaks at a certain diHerence of pressure, and the conse- 

 quent sudden increase of pressure bursts the glass spring manometer. 

 As all attenq)ts to present this enclosure of the liquid phos})horus» 

 failed, and with a few exceptions the experiments miscarried through 

 this circumstance, we have finally trie<l to reach our end by another 

 way, in which w^e have really succeeded. Instead of the statical 

 method we have namely introduced the dynamic method, in the 

 form given to it by S.mitu M. The difticulty was, however, to find 

 a suitable liquid, i. e. a liquid with a comparatively low melting- 

 point, high boiling-point (± 360°j and besides indifferent with respect 

 to the phosphorus. We have succeeded in finding such a liquid, and 

 to this we owe the final success of our endeavours 

 in this direction. This liquid is melted stearin candle 

 material or a mixture of stearic acid and palmitic 

 acid. Instead of the glass spring manometer the 

 apparatus represented in Fig. 4 was now attached 

 to the apparatus Fig. 1. The former consists of 

 a tube a, in which a vessel c is placed with a 

 tube c', which is bent downward and part of which 

 is considerably widened, terminating in a capillary 

 placed in a small wider tube. This apparatus, oi 

 which the xessel* c contains white phosphorus, is 

 quite immersed in the mixture of stearic acid and 

 palmitic acid ; and in the same liquid column, at 

 the level of c is the extremity of the glass tube h 

 fused to at the bottom, in which a thermo- 

 element is placed. The tube a, which contains all 

 this, is fastened airtight by means of a rubber stopper 

 in the wider vessel d, also provided with the same 

 fatty acid mixture, the side tube e of which serves 

 Fig. 4. to enable us to compress the air in d somewhat, 



and to raise the boihng point of the mixture, if necessary. tJy means 



1) Amei-ic. Ghem. Soc 32, 897 (1910). 



