EXPERIMENTAL. 



53 



PROTEIN SOLUBLE IN DILUTE ALCOHOL GUADIN. 



As already stated, wheat flour yields to dilute alcohol a considerable 

 amount of protein matter. Treatment of the residue remaining after ex- 

 tracting the flour with 10 per cent sodium-chloride brine likewise removes a 

 large amount of protein, as does also extraction of the gluten obtained by 

 washing the dough with water. Extracts were made with alcohol under all 

 these conditions, and the protein extracted subjected to repeated fractional 

 precipitations. 



DIRECT EXTRACTION WITH DILUTE AI.COHOI,. 



5000 grams of the straight flour were extracted with 10 liters of alcohol, 

 0.90 sp. gr. , and allowed to soak over night. The next morning the mixture 

 was stirred, and, after settling, the clear solution poured off. Three liters 

 more of alcohol, 0.90 sp. gr., were then added, and after standing some time 

 the supernatant liquid was decanted and the residue squeezed nearly dry. 

 The solution so obtained was designated ' ' extract i . ' ' The residue was 

 again treated with 4 liters of 0.90 sp. gr. alcohol and pressed nearly dry. 

 This formed extract 2. The same process twice repeated gave two extracts 

 which, when united, formed extract 3. Each of these three extracts, after 

 filtering perfectly clear, was separately concentrated to one-third its volume, 

 and, after cooling, decanted from the very glutinous, viscid mass which had 

 separated, i and 3 yielded much more substance than 2. On stirring with 

 a glass rod the precipitated mass formed a very thick, viscid liquid. This 

 substance was in each case dissolved in a small amount of hot alcohol of 0.90 

 sp. gr., in which it was very soluble, and the solution was allowed to cool 

 over night. Most of the substance separated on cooling and the liquid was 

 decanted from it. The solution decanted from the second and third extracts 

 was treated with a quantity of distilled water and a little sodium chloride 

 added. This threw down a small precipitate, which on standing collected 

 on the bottom of the vessel as a clear semi-fluid mass. This was treated 

 with water, absolute alcohol, and ether, and yielded 7.27 grams of prepara- 

 tion 58 from extract 2, and 10.7 grams of the preparation 59 from extract 3. 

 These had the following compositions : 



Preparations 58 and 59. 



