MKMOIKS OF TllK NATIONAL ACADEMY OF 8("IFN("FS. (JM 



separated and weighed was no longer soluble in alci.liol. l)iit lir did not aticinpt aii.\ riirlln-i inves- 

 tigation of its uropeities or tomitosition.* 



Von Bibia, who found in oats 3 i)er cent oi I'Utnt-gcUtthi (I'tlanzenleini), does not descrilie its 

 mode of preparation, but states that it contained l.">.« per cent of nitrogen. 



Kreusler indeed extracted eruslie<i oats directly l)y 80 per cent alcohol, and in iiis lirst impara- 

 tions found lt;.L'2 and ifl.L'l per cent of nitrogen; but 1 he substance, from whose analysis li<- decided 

 upon the composition of 0(tt ;iliiu1iii, had been "imrilicd" by dissolving in acetic acid and pncipi 

 fating by potash solution, and, acctirding to his results, contained l.-'J per cent more idtrogen, 0.05 

 per cent more hydrogen, and 0.« per cent less sulphur than exist in the proteid soluble in alcohol 

 which 1 have analyzed. 



IV. — PROTEIDS EXTRACTED BY WATER. 



The water extract of freshly ground oats has a strong a<:id reaction. The acidity measured 

 by litmus is much less than by phcnol-phthalein. One hundred cc. of an aqueous extract became 

 neutral to delicate litmns paper after adding ten cc. of two-tenths per cent potash solution, and 

 five cc. more of the same solution were added before phenol-phthalieu showed an alkaline reaction. 

 On neutralizing the water extract of oats with two-tentlis per cent potash, using i)henol-phtha- 

 Icin as an indicator, a considerable precipitate ai>peared, which was soluble in tiie slightest excess 

 either of alkali or of the acid contained in the extract. This neutralization precipitate indicates 

 the presence of so-called acid albumin. The perfectly neutralized solution when heated to boiling 

 remained clear. On adding 10 per cent of sodium chloride to the neutralized and filtered licpiid, 

 a considerable precipitate formed upon boiling, as well as on the addition of acetic acid. When 

 the unneutralized extract was boiled and the resulting coagulum filtered of!", neitlier sodium chlo- 

 ride nor acetic acid gave apreciijitatein the filtrate on boiling. The substance remaining in solution 

 after neutralization, but jnecipitated by boiling, in the presence of sodium chloride or on the 

 addition of acetic acid, is a fjlobulii), to be described later. 



The water extract, when heated slowly in a test tube immersed in a beaker of water which in 

 tarn was set in a larger beaker of water, showed a turbidity first at 57° C, and minute tiocks ap- 

 peared at 04° C. Heated to 70° and filtered, the solution renuiined clear until raised to boiling, 

 when a slight precipitate formed. When 10 percent of sodium chloride was added to the extract, 

 the turbidity appeared at 44° C, and flocks formed at 04° C. 



Five pounds of oats were treated with G liters of water for twenty-foiu- hours, pressed out, 

 and extracted a second time for twenty-four hours with the same amount of water. The aqueous 

 extract reacted .strongly acid to litmus, bnt was not neutralized, as tJie possible action of the acid 

 was kept in mind, and the immediate object in view was to find what substances were extracted 

 by the use of water alone. Tlie two extracts were united, saturated with commercial ammonium 

 sulphate and the precipitate thereby resulting was filtered ott', and scraped from the filter, the 

 paper was washed out with water, the solution being added to the dark olive-green precipitate 

 which partly dissolved to a brown solution. After the solution and suspended precipitate had 

 dialyscd for fourteen days in a stream of running water, thymol being added to prevent decompo- 

 sition, the, solution was found to be nearly free from sulphate. The contents of the dialyser were 

 then filtered from a dark green precipitate which had not dissolved on i-emo\ ing the salts. The 

 filtrate was found not to coagulate on boiling, and was evaporated to dryness on the water-bath, 

 leaving a brown residue which weighed between 1 and 2 grams and gave the following reactions: 



With sulphate of copper and caustic potash it yielded a red-pnrple color, of a bluer tint than 

 given by pejitones or proteose, which increased on standing. Millon's reagent with the aiineous 

 solution gave a strong reaction. Alcohol of 0.9 sp. gr. dissolved a portion which, after removal of t he 

 alcohol, was readily soluble in water and reacted for proteids with Millon's reagent and the biuret 

 test. After evaporation of the alcohol on the water bath, the substance was bnt paitiall\- soluble in 

 water. The alcoholic solution was precipitated by adding stronger alcohol. lY'hling's solution gave 

 no reaction until after heating with dilute acid, when a very slight precipitate of cuprous oxide 

 appeared. Very dilute hydrochloric acid gave no i)recipitate in the solution, and stronger acid 

 ~^ "Am. J."Sci. [2] 3, 229. 



