2l8 



THE ALUMNI JOURNAL, 



medicaments with which the phosphorus 

 may be prescribed. It is prepared by 

 dissolving phosphorus, i part, in bisul- 

 phide of carbon 5 parts, adding suet 9 

 parts, mixing thoroughly and allowing 

 the bisulphide to evaporate. It contains 

 the phosphorus in a finely comminuted 

 condition, and if mixed with an equal 

 quantity of compound tragacanth powder 

 together with the other drug — quinine, 

 reduced iron or strychnine — adding a few 

 drops of chloroform, the vapor of which 

 prevents phosphorescence or oxidation — 

 it can readily be massed by the addition 

 of mucilage of acacia or syrup. Such 

 pills, if covered with sandarach solution 

 or pearl coated will keep a reasonable 

 time, but the set, like the liquid prepara- 

 tions of phosphorus, and all pills con- 

 taining phosphorus, are better freshly 

 prepared. This phosphorated suet is 

 unnecessarily strong, and for making 

 compound pills might be replaced by a 

 4 per cent, oil of theobroma solution pro- 

 duced by bisulphide, similar to the 2 per 

 cent, solution previously recommended 

 for an official pill of phosphorus alone. — 

 Phar. /our. 



ESTIMATION OF PHENOL IN SOAPS AND 

 DISINFECTANTS. 



By professor VIRGIIv COBLENTZ. 



Phenol is usually determined readily 

 by the method of Koppeschaar which, as 

 is well-known, depends upon the forma- 

 tion of tribromphenol resulting from the 

 addition of a measured quantity of a 

 standard solution of potassium bromate 

 to acidified (HCl) phenol solution. The 

 excess of the bromine solution being esti- 

 mated by adding potassium iodide and 

 titrating the amount of liberated iodine 

 by means of a standard solution of sodi- 

 um hyposulphite. (See U. S. P.) 



In estimating crude carbolic acid, Kop- 

 peschaar directed that it be digested with 

 water and after the tarry matter had set- 



tled the clear liquid should be examined 

 Toth directs that 20 C. c. of the crude 

 acid should be allowed to stand for one- 

 half hour with 20 C. c. of a concentrated 

 potassium hydrate solution (1.30 sp. gr.) 



it is then diluted with water to 



liter. 



filtered, the filter washed till free from 

 alkaline reaction, then acidified with hy- 

 drochloric acid and the volume made up 

 to 3 liters. Of this an aliquot portion is 

 estimated for phenol content. 



Fresenius recommends this titrimetric 

 method, but directs that the phenol be 

 removed from the substance to be exam- 

 ined by acidifying with hydrochloric acid 

 and distilling in a current of steam, the 

 distillate being titrated directly. In esti- 

 mating phenol in soaps, the author found 

 that traces of the fatty acids were carried 

 over into the distillate which raised the 

 percentage of phenol found slightly. For 

 commercial purposes this may be disre- 

 garded, otherwise a control experiment 

 must be carried out with a soap free from 

 phenol and the amount of bromine con- 

 sumed estimated and deducted from that 

 used in the regular estimation. 



Fresenius employed the following solu- 

 tions : 



[. — Solution containing 9.763 Gm. 

 cry St. sodium hyposulphite in the liter. 



2. — Bromine solution, containing 2.04 

 Gm. of sodium bromate and 6.959 Ova.. 

 of sodium bromide in the liter. 

 3. — Filtered solution of starch. 

 The sodium hyposulphite solution is 

 standardized by means of pure iodine and 

 from this the bromine solution is stand- 

 ardized. 



The .solution containing the phenol to 

 be titrated should not contain more than 

 0.1 Gm. to each 25 C. c. 



The distillation should be carried on 

 in a flask of 600 C c. capacity and as re- 

 ceiver a flask of 500 C. c. 



A sample of soap containing o.i Gm. 

 of phenol, dissolved and acidified with 



