1024 EXPERIMENT STATION RECORD. 



than in any of the other media used. The peat extract medium seemed to be 

 especially favorable for the isolation of the nitrogen-fixing organisms. 



Investigations on capillarity, II. Oli.ivier (Ann. Chun, et Phys., 8. so:, 

 10 il'JOl), Feb., pp. 22D-2SS, flsjs. 11; Mar., pp. 289-321, pis. 3, fi(/s. 22).— The 

 results of these investigations are reported under four heads as follows: (1) 

 Formation of small drops, variations in their weight and form, (2) the influence 

 of compressibility on the formation of drops, (3) contact of water with wet 

 surfaces, and (4) the direct and chronophotographie study of different stages 

 in the regular formation of drops. 



On the source, amount, and importance of carbon dioxid in soils, J. 

 Stoki.asa and A. Ernest (Zfschi: Ziiclcriiirliis. Bohnicu. 31 {1907), No. 5, pp. 

 291-301). — ^leasurements of the carbon dioxid produced in different kinds of 

 soils under a variety of conditions are repoi'ted, the results indicating that the 

 two chief sources of this gas are the respiration of the roots of the higher 

 plants and of the micro-organisms which occur in soils. From the data secured 

 it is estimated that the roots of each wheat plant give off during each day of 

 its period of growth an average of 0.03 gm. of carbon dioxid. It is further 

 estimated that the mici'o-organisms in 1 kg. of cultivated soil respire 15 mg. of 

 carbon dioxid in 24 hours, or 75 kg. per hectare per day for the 200 days of 

 the year in which the temperatiu'e is 15° C. or above. 



On lime concretions, E. Blanck {Laiidir. ^'crs. Stat., 6'> (1901), No. 5-6, 

 pp. J,ll-',19; (thx. in Join: Chem. Soc: [London\, 92 (1901), No. ')3.'i, II, p. 295).— 

 Studies of the chemical composition and absorptive properties of concretions 

 found in calcareous soils are reported. 



The analyses reported show the concretions to consist mainly of calcium 

 carbonate, silica, iron oxid, and alumina, with smaller amounts of various 

 other constituents. Fifty gm. of the fine-ground concretions were shaken up 

 with 200 cc. of tenth-normal potassium nitrate solution containing 0.943 gm. 

 of potash and allowed to stand 48 hours. The absorption of potash was at 

 the rate of 0.1904 gm. per 100 gm. of material and the solution of lime at the 

 rate of 0.109G gm. Treated in the same way with a tenth-normal solution of 

 ammonium chlorid the absorption of niti'ogen was 0.0592 gm. per 100 gm. of 

 material and the solution of lime 0.136 gm. When treated with hundredth- 

 normal monocalciuni phosphate solution 100 gm. of material absorbed 0.52 gm. 

 of phosphoric acid. 



A comparison of ground and unground concretions showed that the absorp- 

 tive capacity for phosphoric acid was greater in case of the latter than in case 

 of the former. These results show that the concretions may exert a marked 

 influence upon the absorptive properties of soils. 



[The effect of] volcanic ash on crops, W. N. Sands (Mo. Conf<iihir anil Trade 

 Rl)ts. [['. aS'.] 1901, -No. 318, p. J,l).—X brief account is given of the decidedly 

 injurious effect on cacao, cotton, pigeon pea, sugar cane, etc., of volcanic ash 

 which fell on tlie Island of St. Vincent during the last eruption of Soufriere. 



The agricultural value of the phosphoric acid of Belgian subsoils, C. 

 ScHREiBER (Iter. (leii. Ai/ron.. n. scr.. 2 (IHOI). No. 1. pi>. 1-S). — The results 

 of a series of pot experiments with typical ferruginous, clay, and sandy sub- 

 soils from different parts of Belgium arc siunmarized, the crops used in the 

 experiments being oats followed by clover. The results show that, while the 

 subsoils contained a considerable percentage (0.02) of phosphoric acid, a very 

 small percentage of it was assimilated by plants, it being apparently iu .such 

 form that it was very slowly dissolved in the soil solutions. 



Availability of phosphates in relation to soil acidity, A. K. Whitson and 

 (_'. W. Stoddart (Wisronsiii tSta. ni)t. 190(1 pp. 111-180. fii/. 1). — Tests of the 

 acidity and fertilizer recpiirements, especially for phosphoric acid, in a large 



