1915] Th. Lissizin 19 



fat-free human hair, and digested it with 6 1. of 2 percent sol. of 

 potassium permanganate. The mixture was allowed to stand for 

 several days, with occasional shaking. The clear fluid was filtered, 

 and the filtrate acidified with hydrochloric acid. The resulting pre- 

 cipitate was washed, first by decantation and then on a filter, redis- 

 solved in dilute soda sol. and precipitated by acidification. The 

 precipitate was thoroughly washed, and dried, first in the air, then 

 in an air-bath at 110° C. The dry substance was weighed and 

 analyzed in the manner described above. 



IL 1.3399 gm. of the substance gave 0.1407 gm. of barium sul- 

 fate (0.01933 gm. of sulfur). 



III. 0.1900 gm. yielded 0.1980 gm. of barium sulfate (0.00272 

 gm. of sulphur). 



The substance contained, therefore, judging from the results of 

 the two analyses, 1.44 percent and 1.43 percent of sulfur, respec- 

 tively. The oxy-proto sulfonic acid from egg-white contains, ac- 

 cording to Maly,^ 1.77 percent of sulfur. Since only a small 

 amount of oxy-proto sulfonic acid resulted from the oxidation of 

 the hair, it is clear that only a small part of the sulfur of the keratin 

 remained in the oxy-proto sulfonic acid. 



In Order to determine how much sulfur is held in the Solution 

 as sulfuric acid, and how much is held in the form of some organic 

 combination, after oxidation by permanganate, I have carried out 

 two parallel experiments on the products of the oxidation. 



In the first experiment, 9.2160 gm. of dry, fat-free hair were 

 digested in 700 c.c. of 2 percent sol. of potassium permanganate. 

 After four days the liquid over the hair was perfectly clear. It 

 was filtered, and from it two portions of 100 c.c. each were taken 

 (IV-V). 



IV. The first portion was evaporated to dryness, treated with 

 dilute hydrochloric acid, and the resultant precipitate of oxy-proto 

 sulfonic acid was repeatedly extracted with water; the filtrate, 

 together with the wash-water, was evaporated, and precipitated 

 with barium chlorid. It yielded 0.040 gm. of barium sulfate (0.0055 

 gm. of sulfur). Therefore, in the 700 c.c, 0.0385 gm. of sulfur 

 was held as sulfuric acid. 



2 Maly : Monatsch. f. Chemie, 1884, viii, p. 255. 



