No. 3, December, 1920] PHYSIOLOGY 195 



the reactions secured l>y Schmiedeberg. The fact that it precipitates spontaneously in water 

 after standing a long time indicates its close relationship to the krepsine "I' Krefting which 

 differs only in that it is insoluble in cool water. Laminarine is found to differ from alpine 

 in that it produces a red precipitate \\ it li alcoholic fuchsin. 1 1 is fermented by yeast and hy- 

 drolysed by many plant enzymes indicating that, it is probably a reserve food of marine algae. 

 — C. II. and 11. A'. Farr. 



1320. Haas, A. R. C. Studies on the reaction of plant juices. Soil Sci. 9: 34] 369. 1 pi., 

 11 fig. 1920. — The actual and total acidities and alkali reserve of a number of agricultural 

 plants were determined. The reaction of the juice of a plant is affected by changes in illum- 

 ination, soil solution, and age. Determination of the actual acidity of alfalfa, alsike clover, 

 barley, buckwdieat, corn, peas, beans, lupines, red clover, mustard, oats, serradella, wheat, 

 and timothy varied from P H 5.19 to P H 6.S0. Determinations on sweet clover showed varia- 

 tions in acidity of 5.S2 in the root to 8.00 in the upper part of the top. Young buckwheat seed- 

 lings showed less acidity than mature plants. A hydrogen-electrode vessel is described, 

 requiring but 3-4 drops of juice. — W . J. Rabbins. 



1321. Jones, H. M. Effect of carbohydrates on amino acid utilization of certain bacteria. 

 Jour. Infect. Diseases 27: 169-172. 1920.— In reply to a paper by Ber.man and Rettger on 

 the effect of sugar upon protein metabolism, the author points out that, in the presence of 

 sufficient carbohydrate, B. proteus shows no evidence of amino acid utilization, even though 

 the reaction of the culture is maintained at neutrality. The softening of gelatin occurring in 

 sugar-gelatin medium, due to the action of bacteria, is an acid rather than an enzymic- 

 hydrolysis, and not a part of protein metabolism. — Selman A. Waksman. 



1322. Myers, C. N., and C. Voegtlin. The chemical isolation of vitamines. Jour. Biol. 

 Chem. 42 : 199-205. 1920. 



1323. Oddo, B., and G. Polacci. Influenza del nucleo pirrolico nella formazione della 

 clorofilla. [The influence of the pyrrole nucleus in the formation of chlorophyll.] Gaz. Chim. 

 Italiana 50: 54-70. Fig. 1-4. 1920. — This is in continuation of a note which appeared in 1915 

 (Gaz. Chim. Ital. 45: 197), and it is an extended discussion of the chemical phase of the ques- 

 tion. After a study of the literature on the question of the importance and function of the 

 pyrrole group in plant and animal (blood) pigments the preparation of a new compound is 

 described. The magnesium salt of pyrrole-carbonic acid is found to have the formula 

 HC— CH HC— CH 



II II II II 



HC C. COO. Mg. OOC CH. This compound was used in the preparation of nutritive solu- 



NH NH 



tions and plants were grown therein. The standard control solution contained the following 

 salts: Ca(N0 3 ) 2 , (NH 4 ) 2 S0 4 , KN0 3 , KH 2 P0 4 . When the newly prepared magnesium pyr- 

 role-carbonate w r as used, the phosphate was omitted and the organic compound used in a 

 concentration equivalent to 0.0232 gm. of Mg. in 1000 cc. of water. Zea mays, Solarium 

 nigrum, Datura stramonium, Euphorbia sp. and Aster sinensis were grown in solutions that 

 were very often renewed. The following conclusions are appended. Plants growm in a nutrient 

 medium free of iron but containing an assimilable pyrrole product form chlorophyll. This is 

 a new phenomenon. Since iron is indispensable to the greening of the plastids, it is here sug- 

 gested that its relation to the process may be one of catalyzer to the formation of the pyrrole 

 nucleus, which in itself is the center of the chlorophyll complex. On the contrary, if this 

 nucleus is already formed, the presence of iron is not indispensable. These experiments con- 

 firm the recent work of Willstatter and that of Eva Mameli. The function of magnesium in 

 the greening of protoplasts is directly proportional to the presence of pyrrole. — A. Bonazzi. 



1324. Okey, Ruth, and Anna W. Williams. On inulin in the globe artichoke. Jour. 

 Amer. Chem. Soc. 42: 1693-1696. 1920. 



