224 PHYSIOLOGY [Bot. Absts., Vol. IV, 



green color with ferric salts is not pyrocatechin. It is a true tannin, giving a precipitate with 

 gelatin, and is, like the oak tannins, derived from pyrocatechin, not from pyrogallol. Heat 

 alone produces pyrocatechin, and no pyrogallol; dilute acids give rise to a phlobaphene and 

 protocatechuic acid, but no ellagic or gallic acids; potash fusion yields protocatechuic acid 

 and acetic acids, but no gallic acid or phloroglucin. — Henry Schmitz. 



METABOLISM (NITROGEN RELATIONS) 



1486. Allen, E. R., and B. S. Davisson. Anall-glass nitrogen apparatus. Ann. Missouri 

 Bot. Gard. 6: 45-48. PI. 2. 1919. — An all-glass nitrogen apparatus was devised for use in 

 nitrogen determinations in connection with the study of the metabolism of soil bacteria and 

 general plant metabolism. Special features of the described apparatus are the absence of 

 rubber connections, the efficient scrubbing of the entrained alkali from the steam, and the 

 use of Pyrex glass which does not yield an appreciable amount of alkali to steam or boiling 

 solutions.— iS. M. Zeller. 



1487. Allen, E. R., and B. S. Davisson. On the relative accuracy of colorlmetric and 

 titrimetric procedures for determining nitrogen as ammonia. Jour. Biol. Chem. 40: 183-197. 

 1919. — Colorimetric procedures in the determination of nitrogen are of service because of their 

 brevity, but except when dealing with minute amounts of nitrogen, titrimetric methods should 

 be chosen where exact results are required. — G. B. Rigg. 



1488. Bottomley, W. B. Nucleic derivatives from peat. Jour. Amer. Peat Soc. 12: 226. 

 1919. — British patent 124329 covers the preparation of nucleic acid and nucleates from peat 

 by means of alkaline solutions. — G. B. Rigg. 



1489. Bracewell, Russell S. The molecular mechanism of colloidal behavior. III. 

 The chemical nature of the adsorption of acids and alkalies by the protein molecule. Jour. 

 Amer. Chem. Soc. 41: 1511-1515. 1919. — The author's work showed that with strong acids 

 and alkalies there is a fairly definite maximum number of equivalents of acid or base adsorbed 

 by fibrin, but the adsorption is not increased greatly by increasing the concentration of the 

 supernatant solution. This supports the idea that adsorption depends on chemical factors. — 

 /. M. Brannon. 



1490. Conn, H. J., and J. W. Bright. Ammonification of manure in soil. New York 

 Agric. Exp. Sta. [Geneva] Tech. Bull. 67. 45 p. 1919.— See Bot. Absts. 3, Entry 850; 4, Entry 

 1643. 



1491. Crocker, William. Reaction of the medium and nitrogen assimilating organisms. 

 [Rev. of: Fred, E. B., and Audrey Davenport. Influence of reaction on nitrogen-assimi- 

 lating bacteria. Jour. Agric. Res. 14: 317-336. 1918 (See Bot. Absts. 2, Entry 169).] Bot. 

 Gaz. 67: 277. 1919. — The reviewer regrets that the reaction was not determined by the gas 

 chain as well as by the colorimetric method. — H. C. Cowles. 



1492. Crocker, William. Nitrogen fixation by Azotobacter. [Rev. of: Hutchinson, 

 H. B. The influence of plant residues on nitrogen fixation and on losses of nitrate in the soil. 

 Jour. Agric. Sci. 9: 92-111. 191S (See Bot. Absts. 2, Entry 583).] Bot. Gaz. 67: 518. 1919. 



1493. Edlbacker, S. Notiz fiber eine Farbreaktion der Eiweisskorper. [A color test 

 for albumen.] Zeitschr. Physiol. Chem. 105: 240-241. 1919. — This new test is very similar 

 to the glyoxylic reaction and seems to be conditioned by the presence of tryptophan. — William 

 Crocker. 



1494. Grunhut, L. Die Bestimmung des Aminosauren-Stickstoffs, insbesondere in 

 Suppenwiirzen und Ersatzbriihwurfeln. [Determination of amino-acid nitrogen.] Zeitschr. 

 I'ntersuch. Nahrungs-U. Genussmittel 37: 204-324. 1919. 



