614 EXPERIMENT STATION RECORD. [yol. 38 



tenth-norraal sulphuric acid. Ttie nitrogen was determined by nesslerization 

 as in tlie usual Folin method. 



The results showed in B. diphtherice 8.35 per cent of nitrogen, and in B. 

 hoffmanni 9.75 per cent. The authors conclude that " it is possible to determine 

 the nitrogen content of any bacterium which will grow on a solid medium with- 

 out liquefaction of that medium, by this method, provided as much material 

 as 5 mg. can be obtained." 



A study of the nonprotein nitrogen of wheat flour, M. J. Blish {Jour. 

 Biol. Chem., S3 (WIS), No. 3, pp. 551-559).— The author, at the Montana Ex- 

 periment Station, has applied the copper protein precipitation method reported 

 by Osborne and Leavenwoth (E. S. R., 37, p. 8) to the separation of protein 

 from nonprotein nitrogen in flour extracts. 



It was found that practically a complete separation may be accomplished in 

 water extracts of wheat flour by treating the extract with tenth-normal sodium 

 hydroxid followed by tenth-normal copper sulphate until there is slightly more 

 copper sulphate than an exactly equivalent amount of sodium hydroxid. The 

 author states that the method is simple of manipulation and permits of rapid 

 filtration through ordinary filter paper, giving a clear solution which may be 

 concenti-ated to one-twentieth its original volume for determinations of amino 

 nitrogen by the Van Slyke micro method and for amid nitrogen determinations. 

 The removal of true proteins is practically complete. Some peptid nitrogen is 

 not precipitated and probably a considerable amount of nonprotein nitrogen 

 which is neither amino-acid nor peptid nitrogen. Normal patent flour was 

 found to contain about 2 mg. of amino-acid nitrogen for every 100 gm. of flour 

 and about three times as much nitrogen in free acid amid form. 



The method is thought to be applicable to studies of proteolysis or other 

 studies involving the estimation of protein cleavage products in wheat flour, 

 but probably will not be applicable to biological extracts from other sources 

 than wheat and flour. 



Copper-phosphate mixtures as sugar reag'ents. A qualitative test and 

 a quantitative titration method for sugar in urine, O. Folin and W. S. J.Ic- 

 Elleoy {Jour. Biol. Chem., 33 {1918), No. 3, pp. 513-519).— A qualitative test 

 for sugar in the urine, employing alkaline phosphates for holding the copper 

 hydroxid in solution, as suggested in a previous investigation (E. S. R., 3G, 

 p. 316), is described as follows: 



One hundred gm. of sodium pyrophosphate, 30 gm. of crystallized disodium 

 phosphate, and 50 gm. of anhydrous sodium carbonate are dissolved in about 1 

 liter of water. To this is added 13 gm. of copper sulphate previously dissolved 

 in 200 cc. of water. The solution is used exactly as is Benedict's reagent for 

 sugar. Minute traces of sugar are indicated by various grades of turbidity, 

 larger amounts by precipitates of cuprous oxid. The test is said to be quite 

 as reliable and sensitive as Benedict's and a trifle more prompt. Unless a 

 marked turbidity is noted in the hot solutions, the result should be regarded as 

 chemically negative. 



The authors also describe a practical and inexpensive quantitative method 

 for the titration of sugar in urine. The reagents are an acidified copper sul- 

 phate solution containing 60 gm. CuSOi.SHoO per liter, and a dry mixture con- 

 taining 100 gm. disodium phosphate crystals (HNa2POi.l2H20), 60 gm. dry 

 sodium carbonate (NazCOa.HjO), and 30 gm. of sodium or potassium sulphocya- 

 nate. The titrations are made in test tubes, which are considered preferable 

 to flasks because (1) the cost of chemicals is reduced, (2) the preliminary 

 heating period is short, (3) there is no necessity of regulating the flame to a 

 definite speed of boiling, (4) the disappearance of the last traces of blue color 



