70 MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 



For comparison the analyses of the last four preparations are here stated together: 



13 and 14, extracted directly by 10 per cent salt solution. 



15, extracted by 10 per ceut salt solution after treating the ground oats witli alcohol, then dis- 

 solved in one-fourth per cent sodium carbonate solution and precipitated by acetic acid. 



16, extracted by two-tenths per cent potash solution after completely exhausting the ground 

 oats with alcohol. 



The four preparations agree in composition so closely that it is fair to assume that they were 

 pure and that the analyses correctly represent the composition of one and the same proteid. 



Of the above analyses, 13 and 14 represent the composition of oat-globulin as extracted by 10 

 per cent solution of the pure sodium chloride and .stUl soluble in that menstruum, while 15 and 

 16 represent the insoluble or "albuminate" modification of the same proteid. 



Analysis of 15 indicates that the globulin is not essentially changed in composition by being 

 dissolved in weak sodium carbonate solution and precipitated therefrom by dilute acid.* 



Since all proteids, except the coagulated, are soluble in weak alkali, the analysis of 16, made 

 on a substance extracted by two-tenths per cent potash solution, may be taken to exhibit the 

 composition of whatever uncoagulated proteids remain in the oat after the direct extraction with 

 weak alcohol. The close agreement of the analysis of 16 with the other analyses leads to the con- 

 clusion that the oat proteids which are not extracted by weak alcohol mainly consist of either the 

 globulin soluble in salt solution or its " albuminate " modification, or else of a proteid from which 

 these are derived under the influence of the solvents employed in their preparation. 



The amount of these preparations obtained in a form suitable for analysis was a very small 

 fraction of the total proteid contained in the oats. This was probably due to the conversion of the 

 globulin into an "albuminate" or a "coagulated proteid." 



The exact cause of this change has not been ascertained. To test the hypothesis that it might 

 be due to the action of an acid or acid salt contained in the oats, 100 grams of the freshly ground 

 grain were treated with 800 cc. of two-tenths per ceut potash .solution. The resulting mixtui'e 

 was neutral to litmus and did not redden phenol-phthalein. Eighty grams of sodium chloride 

 were then added, and the solution, after .standing some time, was filtered. Very little proteid 

 was thus extracted. In another trial 10 -per cent solution of .sodium chloride mixed with two- 

 tenths per cent of sodium carbonate extracted but a small part of the proteids. 



One hundred grams of oats treated with two-tenths per cent solution of sodium carbonate 

 gave an extract <(intaiiiing much proteid, which on addition of a little sodium chloride yielded an 

 abundant priii|)ital(\ Neutralizing the sodium carbonate extract gave a precipitate which was 

 insoluble in sodium chloride solution. 



These experiments indicate that the insolubility of the greater part of the oat proteids in 10 

 per cent brine is not due to the presence of an acid or acid salt. 



Weyl has stated that wlien wheat flour is extracted with .sodium chloride solution, the residue 

 yields no gluten on kneading with water, and he considers that the gluten does not preexist in 

 the wheat, but is a producit of ferment action. It was thought that if a ferment occasioned altera- 

 tion of oat proteids, its effect might perhaps be prevented by treating the ground oats with a 

 sodium chloride solution heated to 75° C, so that all the soluble proteids eoagulable below that 

 temperature would be rendered insoluble and inoperative as ferments. The globulin coagulating 

 at 80° C. ought not to be affected by this treatment. Experiments made to prove this view did 



fusion 



,' figure for sulphur in 15 is a 

 ilkali nitrate and carbonate. 



cidcntal, 8(. 

 The deteri 



loss having been incurred in oxidizing the substance by 

 ition could not be repeated for lack of material. 



