MK.MOIIIS (H- TllK N.V'IIONAL .V< A I >i:.M V ( H' S( 1 KNCK.s. Tf) 



Krciisler's proparatidii of "oaticgumin A" was obtained by su.speiitliii;; lA pounds cru.slied oats 

 in Ti litiMS of water, addiny, to uiMitrali/.o tho acidity, over 3 {grains of potaHsinm hydroxide. Tiic 

 mixture stood twelve lu)ur8 in a cool place, was then thrown on a sieve, the residue washed willi 

 water, and the liipiid left to rest over night. The turl>i<i lii|uid was jjoured oil' and acidilied witii 

 acetie acid. The precipitate was washed first with alcoiiol of l(t per cent, then with that of .SO pei 

 cent, then with ether, and lastly was treated with ai>s(»lute alcidiol and dried over sulphuric acid 

 and at 100^ (!. To i)urify this sui)staiice fnun starch, it was dissolved in dilute potash (1 jriiH" *'» 

 the liter of watxu-), and from the .solutKui, aftiM' deposition of all suspended nuitter, it was thrown 

 down aj;aiu by acetie acid, waslied and dried. 



Another pre])aration, B, was tibtained from oats that had been extracted by cold alcohol — and 

 a third, C, from oats exhausted with hot alcohol— previous to treatment with weak potash .solu- 

 tion. The analyses of A and C, corrected by deduction of ash and phosphoric acrid, are here tat>u- 

 latetl. Ill his preparation B, Kreusler found 1(>.74 per cent of nitrogeu, but carried the analysis 

 no further. 



Norton remarks of his preparation A that dissolving it in hot strong ammonia would .seem lo 

 have darkened tlie color and somewhat affected the <!omposition. It will be observed that Norton's 

 B does not dift'er greatly from my analyses 13 and 19. 



Kren.sler, doubting the purity of his preparation.s, boiled them in alcohol of (JO per cent, and 

 finding that something was thereby dissolved, especially from A, continued this treatment as long 

 as anything was removed. The dissolved substance contained 16.38 per cent of nitrogen. The 

 thus '• purified " preparations had the following composition, ash-free : 



Carbon . 

 H.v.lro^'ci 

 Nitrogen 

 Siilplnir. 

 Oxygen . 



51.85 



51. 40 ' 

 7.49 1 7.49 



17.29 I 17.03 

 0. 



2.97 



22.90 



51. 63 



The average of the last two analyses Kreusler gives as expressing the composition of oat 

 Icgumin.* He observe.s, in concluding his paper, that the substance purified by long boiling with 

 alcohol had almost entirely lost solubility both in i>otash and ac;etic acid. It was in fact converted 

 into coagulated jjioteid; but that the change of composition was not entirely due to the 

 removal of impurities and in part at least was owing to alteration of the substance itself must l»e 

 regarded as almost certain. It is to be concluded that the "globulin " extracted by 1(» per cent 

 •salt solution and the "legumin" removed by dilute potash solution after actitm of water upon 

 the cru.shed grain are very similar, perhaps identical in composition, and that neither of them 



"In a paper already referred to (Pflilger's Archiv, 18, 236), Ritthaiisen decided that the soda-Iiuiemetliod imed liy 

 Kreusler whs untrustworthy, and stated as the ri'.sult of hi.s own analysis liy Duinos's method the nitrogen conliiit of 

 oat IcuHinin to be 17.45 per cent. It is now well understoo<l that DuinoM's method, carried out as Ritthausen describis 

 in the paper relVrred to, usually gives too high results, diio to retention of air in the oxide of co])per, etc., and for- 

 mation of larbon monoxide during the comliiistioii. (Sfv Uejiort Conn. Station, 1878, p. Ill, and 1879, p. 124. 



