1913] Ernest D. Clark 415 



when suspended in the " biuret reagent," was slowly colored blue as 

 the cellulose material absorbed copper f rom the alkaline Solution.^ 



Next, the tannin masses were hydrolyzed with a 2 per cent. 

 hydrochloric acid Solution. The hydrolytic products, when treated 

 in exactly the same manner, gave results identical with those just 

 described. The more concentrated acid seemed to favor the forma- 

 tion of dark-colored products. 



From the foregoing results it appears probable that tannin 

 masses contain tannin and phloroglucinol combined with a third sub- 

 stance, from which union they are released when hydrolysis takes 

 place. The acid gelatinizes that part (colloidal) of the masses 

 which appears to be cellulose or some related substance. 



Hydrolysis of tannin masses with 0.5 per cent. and 5 per 

 Cent, sodium hydroxid Solutions. Treated with 0.5 per cent. or 

 5 per cent. Solution of sodium hydroxid, "tannin masses" gave 

 purplish brown mixtures containing a bulky gelatinous residue, 

 which we removed by filtration. The filtrate was carefully neutral- 

 ized with dilute hydrochloric acid Solution and the reddish brown 

 precipitate that formed was filtered off, washed, and dissolved in 

 water, This liquid was tested for reducing power with Fehllng- 

 Benedict and ammoniacal silver Solutions, both reagents showing 

 weakly positive results. The Molisch reagent, and also ferric 

 chlorid Solution, gave dark non-typical colorations. With vanillin- 

 sulfuric acid Solution a typical red color was produced, when the 

 liquid was evaporated. 



The Solution of the material not precipitated from alkaline Solu- 

 tion by acid was now tested in the usual way for reducing power, 

 presence of phloroglucinol, etc., with uncertain results, due to the 

 dark color of the Solution. When alkaline Solutions of the hydro- 

 lytic products are exposed to the air, oxidation seems to occur and 

 dark complex substances are formed. The gelatinous material 

 which resisted hydrolysis was filtered and washed. It appeared to 

 consist of the collapsed cell-walls of tannin masses. When dried it 

 formed a light-colored scaly mass composed of small particles. On 

 the whole, the results of alkaline treatment of the tannin masses 



^Kantor and Gies: Biochemical Bulletin, 191 i, i, p. 269. 



