No. 1, August, 19*20) PHYSIOLOGY 1 2 1 



874. Bunker, J. W. M. The determination of hydrogen ion concentration. Jour. Biol. 

 Chem. 41: 11-14. 1920. -An electrode and a vessel .tie described which have been in use a 

 long time, meeting the requirements of quick, accurate determinations in large numbers. — 

 G. B. Rigg. 



875. Church, A. H. The ionic phase of the sea. New Phytol. 18: 239-217. 19J9.— 

 This is a discussion of sea water as the "primary source of 'life' "from the standpoint of the 

 modern physico-chemist. The ionization of the salt content of sea water is discussed, par- 

 ticularly in relation to the ions of carbonic acid. Far-reaching analogies are pointed out 

 between living substance and sea water; the latter is even considered to be "the primordial 

 material of which protoplasmic units are but individualized particles or segregated centres 

 of actions, still more complex, but of the same category." — /. F. Lewis. 



S76. Clevenger, Clinton B. Hydrogen-ion concentration of plant juices. I. The 

 accurate determination of the hydrogen-ion concentration of plant juices by means of the hydro- 

 gen electrode. Soil Sci. 8: 217-226. 1919. — The apparatus is essentially that described by 

 Clark and Lubs with modifications to prevent foaming of the plant juice and to simplify both 

 the shaking apparatus and the temperature. To prevent contact between the electrodes 

 and plant juice during saturation with hydrogen the juice is placed in dropping funnels at- 

 tached to the electrode vessels. To reduce contact potential, contact between the plant 

 juice and the saturated potassium chloride solution is made by means of a scratch around the 

 cock connecting the two. Duplicate measurements agree within 0.1 millivolt. — William J. 

 Robbins. 



877. Clevenger, Clinton B. Hydrogen-ion concentration of plant juices. II. Factors 

 affecting the acidity or hydrogen-ion concentration of plant juices. Soil Sci. 8: 227-242. 1919. 

 — Determinations of acidity should be made as quickly as possible after cutting the plant 

 and extracting the juice, as the acidity of plant juice may decrease or increase on standing. 

 The roots of cow pea are generally more acid than the leaves and the leaves more acid than the 

 stems. The acidity in the roots of cow pea during a 24 hour period is rather constant, being 

 higher during the day. In the leaves and stems the acidity drops during the afternoon, 

 rising during the night and reaching a maximum in the morning. The acidity of the roots 

 of plants appears to be correlated with the reaction of the soil, but the acidity of the tops 

 of the plants studied was greater on limed than on unlimed soil. — William J. Robbins. 



878. Colin, H. Utilization du glucose et du levulose par les plantes superieures. [Utili- 

 zation of glucose and levulose by higher plants.] Compt. Rend. Acad. Sci. Paris 168: 697-699. 

 1919. — The proportion of glucose to levulose in green leaves of beet is often less than 1, but 

 increases down the midrib and in the petiole. Etiolated leaves of beet, artichoke, and chicory 

 showed a larger proportion of dextrose than of levulose, whereas in the storage organs of these 

 plants the reverse is true. It is assumed that these two sugars must either be transported 

 at unequal rates or that they are utilized in unequal amounts. The author concludes that it 

 is more probable that the glucose is oxidized in the cell in preference to levulose, the latter 

 playing an essential role in tissue formation. Thus respiration is less intense in the petiole 

 than in the blade, and less in etiolated leaves than in green leaves. — F. B. Wann. 



879. Cushny, Arthur R. The properties of optical isomers from the biological side. 

 Pharm. Jour. 103: 483. 1919. — The living plant discriminates between laevo and dextro- 

 rotatory bodies because it is itself optically active, but no optically active substances have as 

 yet been synthetically produced by man. Because of this phenomenon of discrimination by 

 the living plant and the fact that an optically active alkaloid, such as cinchonine, can be used 

 to separate a mixture of laevo and dextro tartrates, and the further fact that vegetable and 

 animal organisms that act upon asymmetric bodies generally destroy the substance that occurs 

 in nature but will not destroy the non-natural isomer", the author declares that "until life 

 appeared no optically active body existed, and without life and its products there would be 

 none today." Further, this optical activity is the most persistent evidence of life, since an 



