112 EXPERIMENT STATION RECOED. t Vol. 37 



200 cc. with water. After standing for about an hour this solution Is ready for 

 use. A solution kept in a closed container for six weeks was found to be as 

 reliable at the end of that time as a freshly prepared solution. 



When formaldehyde is present in the solution to be tested it should be accu- 

 rately determined and the same amount used in the standards. 



Cellulose, C. F. Cboss, E. J. Bevan, and C. Beadle {London and New York: 

 Longmans, Green d Co., 1916, new ed., XVII +328, pig. H). — This edition is in 

 the main a reprint of the former edition with a small portion of the text re- 

 written and the addition of an appendix which Includes an account of the more 

 important recent contributions. The subject as a whole treats of the chemistry 

 of the structural elements of plants with reference to their natural history and 

 industrial uses, and is divided into three parts, the typical cellulose and the 

 cellulose group, compound celluloses, and experimental and applied chemistry. 



A quantitative m^ethod for the determination of arg-inin in proteins, B. C. 

 P. Jansen {Chem. Weckbl, U (1917), No. Jf, pp- 125-129).— A new method is 

 proposed which consists of hydrolyzing a suitable sample of protein with hydro- 

 chloric acid (specific gravity 1.19), removing as much of the excess hydrochloric 

 acid as possible by evaporation, and neutralizing the hydrolyzate with alkali 

 until .slightly alkaline to litmus or neutral to neutral red. Aliquot portions are 

 then treated simultaneously with solutions of arginase and urease for about 

 24 liours, after which time tlie anmionia from the ammunluui carbonate formed 

 is liberated by a saturatetl solution of potassium carbonate and distilled by 

 aeration into standard acid. A blank determination is made with an aliquot 

 and urease alone to determine the presence and amount of urea in the hydro- 

 lyzate. One molecule of arginin yields oue molecule of ornithin and urea, so 

 that the amount of arginin originally present is readily calculated from the 

 amount of ammonia obtained. 



The method is considered to yield more accurate results than the procedure 

 of boiling the hydrolyzate with alkali as described by Van Slyke (E. S. K., 26, 

 p. 22). 



The preparation of the arginase from the fresh liver of a dog or cat Is 

 described in detail. 



Red peppers, F. M. Boyles (Jour. Indus, and Engin. Chem., 9 (/9/7), No. S, 

 pp. 301, 302). — Analytical data of a number of .samples of South Carolina 

 capsicum, Bombay capsicum, Japan capsicum, Mombasa chilies, and miscella- 

 neous capsicums and chilies are reported In tabular form. The data include 

 total a.sh, insoluble ash, fiber, total ether extract, and volatile and nonvolatile 

 ether extract. 



It is indicated that the pre.sent standards for red peppers (E. S. R.. 18, p. 4r>9) 

 are in nood of revision and the following Is submitted: Total ash 7.5 per cent, 

 hydrochloric acid-insoluble ash 1 per cent, nonvolatile ether extract 14 per cent, 

 and crude fiber 29 per cent. 



Vinegar: Its manufacture and examination, C. A. Mitchell (London: 

 Charles (Jriffln d- Co.. Ltd., 1916, pp. XVI +201, pis. 5, figs. 49).— This volume 

 discusses the subject In detail under the general topics of historical introduc- 

 tion, theories of acetic fermentation, acetic bacteria, chemical reactions in acetl- 

 flcatlon, acetic acid, preparation and acetificatlon of the gyle, treatment of the 

 crude vinegar, methods of examination, and characteri.stlcs of different vinegars. 

 Appendixes contain British Import duties on vinegar and acetic acid and French 

 duties on vinegar. 



The volatile reducing substance in cider vinegar, R. W. Balcom (Jour. 

 Amer. Chem. fioc.. 39 (1911), No. 2, pp. 309-31.')).— The author has shown that 

 the volatile reducing substances In cider vinegar consist largely, if not wholly, 



