44 AET. 12. — IT. TTTROBE : ON THE FUSION SURFACES OF THE 



of bromine-water as constant as possible, yet we tested it for 

 the salve of control before and after eacli observation. It was 

 constant up to about 0.02 c.c. of the sodium tliiosulphate solution, 

 of which 40 c.c. was used in each titration. The lower end of 

 the pipette connected with the syphon tube was dipped in the 

 solution containing phenol, while bromine-water was allowed to 

 run into it. This hindered the bromine from evaporating, and 

 consequently made tiie titration more constant. 



The aqueous solution of phenol was first separated by suck- 

 in«: it from under the chlorobenzene, since the salt solution was 

 heavier than the chlorobenzene. 2 c.c. or 5 c.c. of the aqueous 

 solution was taken by means of a pipitte with a cotton wool 

 filter at the end, and put into a bottle of 300 c.c. capacity with 

 a well fitting glass stopper, and 50 c.c. of pure Avater and 2 c.c. 

 of chlorobenzene or chloroform were added. On admitting bromine- 

 water into the bottle, a white flocky precipitate was produced, 

 which on shaking vigorously dissolved completely in the oil, the 

 greater part of the remaining bromine went to it and there was 

 little fear of losing it by evaporation. After about 15 minutes 

 the necessary quantity of potassium iodide solution was added 

 and well shaken, then the iodine set free was titrated with 0.03 

 normal solution of sodium thiosulphate, chloroform or chloroben- 

 zene functionating as an indicator. The partition coefificient was 

 observed at three difierent temperatures 25°, 45°, 65°, the tem- 

 peratures were maintained in a thermostat and were constant to 

 0.1° durins: observation. The most concentrated solution in 

 chlorobenzene contained 50°/o of phenol. This was made by 

 taking equal quantities by weight. The mixture was diluted with 

 various proportions of chlorobenzene, seven solutions in all being 

 prepared with percentages of phenol varying between ö'^/o and 50^/o. 



