MEMOIKS OF TUE NATIONAL ACADEMY OF aClE^'CKS. 



59 



Oil t lie authority of Rittliauseii, bis names and llie coHiiiosition attributoil by biiii to Ibesc 

 siibstaiucs liave passed into cliouiical literature, and liave superseded tbt^ various desij^natioiis 

 and analyses of the older investi;,'ators. 



The proteid of tiie oat wiiieb I have obtained, soluble in alcohol, difl'ers essentially, however, in 

 ooniposition from all these prei)arations of Uitthaiiseu and Kreusler. Ivreiisler's analysis of 

 inueedin from barley grits alone fairly agrees with my results as respeets carbon, hydrogen, and 

 nitrogen, but the same ehemist's analysis of nun-ediii from barley meal gives 0.S4 per cent higher 

 nitrogen than that from grits, and i)iit (t.(!8 per cent sulphur. 



In case of the other substauces tlie discrepancies are still more decided. The i)ropertie8 and 

 reactions given by Kreusler for the substance called by him natgliadin are true of the body Just 

 (lescrilied, but these reactions mostly belong to proteids in general, or to the mucedin and librin of 

 Ritthausen, and are not characteristic of any one body. Ritthausen states that on evaporating 

 the alcohol solution of the gluten fibrin jnepared by him from wheatgluten, a pellicle forma on the 

 siu-face which renews itself as often as removed, and that neither mucedin nor gliadin shows tiiis 

 property. I have freqiieiitly observed the formation of films on evaporating solutions »f the 

 alcohol soluble proteid from oats. This body, however, can not be a mixture of Ritthausen's 

 librin and gliadin, as its sulphur content so largely exceeds theirs. 



2. EXTRACTION WITH ALCOHOL APTEK TREATMENT WITH WATER. 



(Proparation 9.) 



Five pounds of oats were treated with \Yater as long as any proteid was dissolved. The resi- 

 due was then twice extracted with alcohol and strongly pressed. The first alcoholic extract was 

 evaporated so far as to remove nearly all the alcoh<d. On cooling, the solution became turbid, and 

 after standing deposited a brown, slimy substance exceedingly soluble in dilute alcohol. The li(|uid 

 was decanted and the precipitate dissolved in dilute alcohol. Aft<^r evaporating off the alcohol 

 and cooling, the substance separated as before; the aqueous solution was decanted and the slimy 

 residue treated with etlier, which extracted a fatty oil from this material and caused it to assume 

 a more solid consistence. The substance was then treated with alcohol of ().'5 per cent, which 

 dissolved a little and converted the remainder into a solid lumj), so that it could be transferred to a 

 flask and digested with ether. Uy the continued action of ether the viscid substance was trans- 

 formed into a loose, yellowish powder. After .standing under ether for twenty-four hours, the 

 body was filtered out and dissolved in dilute alcohol. This alcoholic solution was filtered and 

 evaporated on the water-bath to a small volume. After cooling, the solution was poured from the 

 gummy substance adhering to the di.sli, which was washed with water and repeatedly digested 

 with absolute alcohol. As long as tlie substance retained water, a little dissolved during treat- 

 ment with alcohol. The residue becaiiie granular and brittle, and was easily reduced to a line 

 powder. When impregnated with absuliite alcohol the mass rapidly absorbed moisture from the 

 air and became soft and viscid. 



After thorough dehydration with absolute alcohol tlie substancte was rapidly filtered out and 

 dried over sulphuric acid. It weighed 7.8.S grams. 



In testing the purity of this substance it was found to yield something to water. The whole 

 preparation was, therefore, washed out completely with distilled water, and again treated with 

 absolute alcohol and ether and dried over sulphuric acid. Analysis of this preparation (9) gave 

 the following results : 



Sulublc proteid extracted by weak ak-oholfrom ground oats after treating them irilh irnfrr (£ 



