M. J. Blish 050 
gave a slight color with Nessler’s reagent, indicating but a trace 
of free ammonia. Amino nitrogen was determined in Van 
Slyke’s micro-apparatus using 5 ce. portions of Solution X. Amide 
nitrogen was determined by diluting 50 cc. of Solution X to 100 
ec., boiling for 2 hours with 2.5 ce. of concentrated sulfuric acid, 
according to the method of Kénig,’ and distilling with an excess 
of calcium hydroxide under reduced pressure. In order to find 
out approximately the nature of the rest of the nitrogen in the 
extracts, 25 cc. portions of Solution X were hydrolyzed with 
strong hydrochloric acid for about 12 hours, after which am- 
monia and amino nitrogen were again determined, and the in- 
crease in these constituents over the amounts as determined 
before hydrolysis was considered as indicative of the nature and 
complexity of any nitrogen compounds still present in peptide or 
protein form. In Table II are presented results of analyses of 
flours A and B. 
TABLE II. 
[ Flour A | Flour B 
Constituent determined. (sound | (slightly | Flour A.| Flour B. 
‘ patent). | frosted). 
per cent per cent gm, gm. 
PRG Oee MOU ALOUT HC tan ce emarits cm 6 su es 1.89 1.79 
Per cent of total N of flour extracted 
by distilled CO:-free water in 25 
FS (AGS ope. eels ge ae CA ER LA, a - 16.06 | 15.40 
Per cent of total flour N not precipi- |° 
CALE OY? COPED a. ae sat. «ne oe aa aye eae 1.62 ZA12 
Free ammonia in Solution X.......... Trace. | Trace. 
Amide N in total ‘‘non-protein’’ N..:.| 20.00} 26.12 
Gm. of amide N in 100 gm. of flour..... 0.006 | 0.0095 
a-Amino N in total ‘‘non-protein’’ N.. 6.62 7.79 
Gm. of amino N in 106 em. of flour.... 0.002 | 0.003 
Ammonia N after hydrolysis.......... 10.91 | 10.382 
a-Amino N increase due to hydrolysis.| 19.34 | 20.22 
Humin N after hydrolysis............. 8.16 aa t 
Residual nitrogen by difference........| 34.97 | 28.18 
It will be observed from Table II that the actual quantity of 
free amino nitrogen in a normal flour is exceedingly small, being 
about 2 mg. for every 100 gm. of flour. There is about three 
3 Kénig, J.,; Chemie der menschlichen Nahrungs- und Genussmittel, 
Berlin, 4th edition,“1910, ili, 274. 
