WATER — SOILS. 535 



were imuU'with l)()(h artificial and soil huiiiic acid. Tlic Iniiiiic acid wan used cither 

 ill jelly-like condition or (juite dry. The absorption of nitrojreii from anunoniuni 

 carbonate and aninioninin .snlphate wa.s attempted. The experiments were con- 

 ducted as follows: Three to 5 gm. of dry hnniic acid (or an equivalent amount of the 

 gelatinous preparation) was mixed in a flask with 100 cc. of a 10 per cent solution of 

 annnonia salt and allowed to stand for a certain number of days with frequent 

 shaking. One series of flasks of each kind of mixture was examined after 24 hours, 

 another at the end of 7 days, and another after a month. In these examinations 

 the unchanged annnonia salt was first removed and then determinations were made 

 of the total and the amid nitrogen. The author sums up the results of his experi- 

 ments as follows: (1) Absorption proceeds most energetically when the humic acid 

 is soluble in the ammonia salt used, somewhat less energetically when freshly pre- 

 cipitated humic acid is used in comiection with an ammonia salt in which it is not 

 soluble, and least when dry humic acid reacts with an anmionia salt in which it is 

 not soluble. (2) The energy of absorption is expressed solely by the rapidity of the 

 reaction, the amount of absorbed nitrogen being the same in all cases. In the first 

 case the absorption attains its limit in a short time, while in other cases the same 

 limit is reached after a longer period of time. (3) In cases where the humic acid is 

 not soluble in the ammonia salt the concentration of the solution of the latter is of 

 importance, the rapidity of absorption varying with the concentration. (4) The 

 absorbed nitrogen gives rise to the formation of amids almost exclusively. The 

 absorption was approximately 1 to I5 per cent when soil humic acid was used. — 



p. FIREMAN. 



The nitrifying capacity of normal soils and the loss of nitrates through 

 drainage, A. V. Klucharov {Jzv. Moscow Selsk. Khoz. Inst. [Arm. Inst. Agron. 

 Moscou'}, 6 {1900), No. 2, pp. 132-166).— In order to overcome the effect on nitrifi- 

 cation of the stirring and aeration of soils, which, in the opinion of the author, has 

 led to too high results in many of the investigations reported on this subject, a study 

 of soils in their natural state was attempted as follows: Thin-walled steel cylinders 

 open at both ends, 11 cm. in diameter and 20 cm. in height, sharpened at the lower 

 end, were carefully pressed into the soil to the top and then withdrawn with the 

 inclosed soil. A zinc funnel was slipped on the lower end of the cylinders and 

 luted to the latter. The percolating water was collected in a separatory funnel. 

 The cylinders with the inclosed soil were lowered into thin-walled iron cylinders, 

 50 cm. high, sunk in the ground. The steel cylinders were made to fit tightly within 

 the iron ones and precautions were taken to prevent the rain water from getting in 

 between the soil and the walls of the cylinders and between the steel and iron 

 cylinders. 



In the experiments reported there were determined (1) the amount of nitrates in 

 a control cylinder of the soil at the beginning, (2) that percolating through the soil 

 during a definite period of the experiment, and (3) the amount in the soil at the 

 end. Observations showed that the temperature, humidity, and porosity of the soil 

 in the cylinders were the same as in the normal soil. 



Investigations were made in 1895 with 6 soils: No. 1. — Soil from the experiment 

 field of the Moscow Agricultural Institute, a very rich clay soil which had been 

 frecjuently manured with large (juantities of barnyard manure, upper layer strongly 

 colored by humus substances. No. 4. — Soil from a turf meadow on the Zhabinka 

 River, brown in color, passing not infrecjuently into red yellow. No. 6. — Soil from 

 the farm of the institute, of the same type as No. 1, but less liberally manured. 

 No. 7. — Soil from a field in the viciniy of the institute, a clayey, light yellow, poor 

 soil which had been little manured and badl}' cultivated. No. 5. — Soil of thepodzol 

 type from the forest of the institute, light gray in color, excei)t a thin layer on the 

 surface, which was somewhat darker in color. No. 9. — A sandy, slightly coherent soil. 



