64 MEMOmS OF THE NATIONAL ACADEMY OF SCIENCES. 



made a slight turbidity. These reactions indicate presence of a proteone and absence of true 

 alhumin. 



Tlie substance remaining after dialyzing the amniouiam-sulphate i^recipitate was treated with 

 10 per cent brine of sodium chloride; the resulting solution was filtered off and dialyzed till free 

 from chlorides. Nothmg precipitated on removal of the salt, the proteid being soluble in water. 

 This fact shows that no globulin had been extracted from the substance which separated oa 

 dialysis of the aqueous extract, the globulin having been converted into an insoluble form. Thi'j 

 dialyzed sohition was not coagulated by boiling, and was therefore evaporated to dryness on the 

 water bath. The residue, weighing about 1 gram, was not quite completely soluble in water. As 

 much as possible w^s dissolved in a small amount of water, and filtered ft-om a slight residue. The 

 solution was colored deep yellow-brown, contained a trace of chlorides, gave no precipitate with 

 hydrochloric acid, either very dilute or strong. No biuret reaction was discernible in the colored 

 solution, which gave the proteid coloration with Millon's test, and did not reduce Fehling's solution 

 before treatment with acids. On long standing, after heating with hydrochloric acid, a little 

 cuprous oxide separated. Evidently this substance is the same {proteose f ) as that obtained from 

 the solution remaining after dialyzing the ammonium sulphate precipitate. 



The substance remaining after dialysis and insoluble both in water and in 10 per cent brine 

 was found to be partly taken up in one-half per cent sodium carbonate solution and in dilute 

 hydrochloric acid, being the result of the alteration of globulin, which had passed into soluti(m 

 by means of the salts derived from the oats. The neutralization precipitate from sodium carbonate 

 solution was slightly soluble in 10 per cent brine of sodium chloride. The fact that the ammonium 

 sulphate used in this work was crude and had a slightly acid reaction and a bluish tint, to which 

 the green color of the jjrecipitate was due, may throw doubt on the results hei'e recorded, but as 

 they were mostly corroborated on i-epeating the trials with pure and neutral ammonium sulphate, 

 I have given them in detail. 



The results of a second examination of proteids soluble in water here follow : Five pounds of 

 oats were treated with 7 liters of water for forty-eight hours, thrown on a sieve, the residue pressed 

 out and treated for a short time with G liters more of water. The two extracts were united and 

 allowed to settle, when the nearly clear liquid was syi)honed off and saturated with pure 

 ammonium sulphate. After the white precipitate thus produced had stood over night, it separated 

 in large flocks from the liquid, and was filtered out and dissolved mostly in 10 per cent sodium 

 chloride brine, filtered, and the clear solution dialyzed. The precipitate was not completely 

 soluble in 10 per cent sodium chloride brine nor in water — in these respects resembUug the 

 precipitate obtained from the first extract after it had been dialyzed. The clear, filtered solution 

 in 10 per cent sodium chloride brine, on standing, slowly deposited a part of the dissolved sub- 

 stance. The solution, with the precipitate which had formed, was dialyzed until free from salts, 

 and the solution after filtering again was evaporated to dryness on the water bath, leaving a 

 residue of 1.11 grams. The preciiiitate filtered out was quite small in amount. The total pioteid 

 obtained by saturating with ammonium sulphate was less thau that got in the first extraction, 

 probably because the oats were allowed to stand twice as long in contact with water as in the 

 case of the first extract, for it was found that the clear, filtered extract of the ammonium sulphate 

 precipitate in 10 per cent sodium chloride brine, on standing, deposited the dissolved substance, 

 so that before the conclusion of the dialysis nearly all the proteid originally soluble in water had 

 lost its solubility. 



Weyl states that water converts vegetable globulins into "albuminates ;" that is, 'into forms 

 no longer soluble in salt solutions, but soluble in 1 per cent sodinm carbonate solution or 0.8 per 

 cent hydrochloric acid, and that a long-continued action of wat6r finally converts the albuminates 

 thus i)roduced into modifications that are no longer soluble in 1 per cent sodium carbonate solu- 

 tion or 0.8 per cent hydi'ochloric acid. They are then not to be distinguished from "coagulated 

 proteids." This latter change he has observed only for the globulins of peas and oats. 



Transformations of this character occurred in the two extracts jnst described. In the first, 

 after dialysis, the residue insoluble iji 10 per cent sodium chloride brine was partly soluble in one- 

 half per cent sodium carbonate solution, and in tlie second a body was formed insoluble in water 

 and in 10 per cent sodium chloride brine, but soluble in one-half per cent sodium carbonate 

 solution. 



