612 EXPERIMENT STATION RECORD. T Vol 40 



and then with phenolphthalein as indicators, the former representing acidity 

 due to free acids and acid salts and the latter, total acidity. 



In applying the method of double titration to the study of the preexisting 

 acidity of barley, it was observed that barleys not fully matured by storage 

 showed a higher total than litmus acidity, while for those which had undergone 

 afterripening the litmus acidity was practically the same as the total acidity, 

 indicating a disappearance of amino acids during the process of afterripening. 

 It is suggested that practical identity of the litmus and total acidity, when 

 determined on mashes prepared by alcoholic extraction, is a mark of complete 

 ripeness in a barley and therefore of its fitness for malting. 



Experiments were also conducted with a view to finding a quantitative 

 measure of the enzymic strength of barley in the acidity developed by enzymic 

 processes when the ground barley is digested with water for 15 hours at from 

 18 to 19° C. The acidity developed during digestion was found to be chiefly due 

 to the formation of substances which react acid toward phenolphthalein but not 

 toward litmus. The results appear to indicate that this increase of acidity 

 during digestion may vary from year to year. For barleys of the same year, 

 it is in general greater for those of high than for those of low germinating 

 power. 



Detection of milk in pastry, J. Grosskei.d (Ztschr. Untcrxuch. Xahr. u. 

 Genussmtl, S5 (1918), No. 12, pp. 457-471 ) .— The method used depends on the 

 conversion of lactose into mucic acid. The lactose is removed from the sample 

 by extraction with water. The filtrate is evaporated to a thin sirup with the 

 addition of 5 cc. of glacial acetic acid. This sirup Is treated with 00 per 

 cent alcohol, filtered, and the filtrate evaporated to dryness. If a large quantity 

 of sucrose is present, this Is removed by dissolving the dried residue in alcohol 

 and adding an equal value of ether. After standing 24 hours the sugars are 

 collected and again treated with alcohol and ether. The precipitated lactose 

 is heated with nitric acid and the solution filtered. Mucic acid will crystallize 

 out, usually within 24 hours. About 30 per cent of the lactose present will be 

 converted into mucic" acid. 



The calcium content of pastry may also afford some Indication as to whether 

 milk has been used in its preparation. Pastry made without milk may contain 

 0.2 per cent of calcium oxid calculated on the dry substance. 



The estimation of cacao shell. A. W. Knapp and B. G. McI.kt.t.an (Analyst, 

 44 (1919), No. 514, PP- 2-22). — This is a critical discussion of the various proc- 

 esses suggested for the estimation of cacao shell, with an explanation of factors 

 Influencing the different methods or the limitations of their accuracy. Tables 

 are given of the results obtained in the determination of crude fiber, nitrogen, 

 pentosans, and ash. 



The conclusion is drawn that the chief difficulties in the way of an accurate 

 determination of* cacao shell are "the natural variation In cacao shell due to 

 botanic variety and the distinctive treatment which the bean receives in each 

 country and that cacao shell Is not a definite chemical substance, and hence 

 the estimation can only be of a purely empirical character." The only method 

 employed by itself which is capable of giving results of any value is considered 

 to be the estimation of the crude fiber. 



Detection of adulterations in maple products, C. H. Jones (Pror. 17. Mnjtlr 

 Sugar Makers' Assoc, 24 (1917), pp. 25-S0).—A brief description is given of the 

 methods in use for detecting adulteration In maple sugar and sirup. A table 

 is included of the percentage of total ash, insoluble ash, and malic acid in 

 various sugars. 



