Physiologie. 293 



The data show clearly that carbon bisulphid does not act alike 

 in all soils or toward all crops. M. J. Sirks (Wageningen). 



Headley, F. B. and C. S. Scofield. Effect on plant growth 

 of sodium salts in the so il. (Journ. agric. Research. Washing- 

 ton. VI. p. 857—869. 1916.) 



In reclaiming a tract of salt land in Nevada laboratory expe- 

 riments were carried on to determine the limits of tolerance of 

 certain crop plants to the common salts of sodium. Ordinary drink- 

 ing glasses were filled with 300 gm. of air-dried soil. The salts 

 were added from a stock Solution of known strength and ranged in 

 amount from nothing up to concentrations sufificienlly strong to 

 present plant growth entirely. Distilled water was added to each 

 glass and after germination the number of plants was reduced to 

 five if more than that number came up. The wheat was allowed to 

 grow from 15 to 18 days, when the plants were cut at the surface 

 of the ground and weighed immediately in a closed tube. After 

 cutting the plants the soils from each series of glasses were mixed, 

 dried, and analyzed for water-soluble salts. 



These laboratory experiments brought out the fact that only a 

 part of the salt added to the soil in pot cultures could later be 

 recovered from it by water digestion. This apparent loss of salt, 

 which was probably due to absorption by the soil, was greater in 

 che case of sodium carbonate and sodium sulphate than with sodium 

 Chlorid. 



Where sodium carbonate was added to a soil the absorption 

 was greater in fine soil, rieh in organic matter, than in sand. 



The limit of tolerance of crop plants to the salt in the soil is 

 determined b}^ the quantity of salt that can be recovered from the 

 soil rather than by the quantity added to the soil. The carbonates 

 and bicarbonates of sodium are mutually interchangeable in the soil 

 and the toxicity of the soil Solution appears to depend upon the 

 quantity of the basic radical held in the soil regardless of the form 

 of the acid radical. 



In the case of the soil from the field under consideration, the 

 Proportion of recoverable salt which would reduce by one-half the 

 growth of wheat seedlings was for the carbonates 0,04 per cent of 

 the dryweight of the soil, for the chlorids 0,16 per cent, and for 

 the sulphates 0,35 per cent. The proportion of recoverable salt 

 which prevented germination of wheat was for the carbonates 0,13 

 per cent, for the chlorids 0,52 per cent and for the sulphates 0,56 

 per cent. M. J. Sirks (Wageningen). 



Kanngiesser, Fr., Ueber Lebensdauer einiger Sträucher. 

 (Ber. Deutsch, pharmaz. Ges. XXIV. p. 312—313'. 1914.) 



Das grösste beobachtete Alter in Jahren ist bei Calhma 23 Jahre, 

 bei Vacciniuni myrtillns 12, Helianthemum vulgare 12, Teiicrium 

 inontanum 20, Juniperus communis 117, UlexeuropaeusXb^Rhamnus 

 pianüa 61, Rhododendron ferrugineum 65. Matouschek (Wien). 



Toulaikov, N., Der osmotische Druck der Bodenlösung 

 und die Glasigkeit des „Bielo tourka"- Weize ns. (Rund- 

 schau experim. Landw. XVII. 1. p. 79—91. Petersburg 1916.) 



Die Versuchsreihen seit 1913 ergaben: Von der Glasigkeit des 



