1248 



son, PHYSICS, CHEMISTRY AXD MICROBIOLOGY 



958 - Reorganisation of Agricultural Education in Colombia. — Revhia a<;ncoUi, Orgam 



del ]\Iimstcri(j dc Ai^ricultura y Cdincrcia, Iltid Year, Xo. 1, p. 65. Bogota, I-'ebruary 1916. 



Decree No. 123 of the 31st January 1916 provides for the reorganisa- 

 tion of the National Agricultural and Veterinary Institute under the name 

 of " Institute nacional de Agronomia ". The following are to form part 

 of the National Agronomic Institute : the practical schools of Agriculture, 

 the stations of scientific agriculture and experimental fields, founded in 

 the capital or in other localities of the Republic. The director of the School 

 and the technical chiefs of the experimental services of the Station of scien- 

 tific agriculture will form the technical Council of the corresponding Station 

 which must reply to enqviiries by the Ministry of Agriculture and Commerce, 

 as well as to those of the public, on questions of scientific agriculture, 

 livestock and protection of plants against diseases and pests. 



CROPS AND CUI.TIVATION. 



SOIL PHYSICS, 



CHEMISTRY 



AND 



MICROBIOLOGY 



959 - Contribution to the Study of the Forms in which Phosphoric Acid occurs in the 



Soil. — JEGOROV M. A., iu lOjiCHn-pt/rehofi '■i'.ihch'n-.vns!ii(c)ii6eHH(Ui Fd-icmn [The 

 Agricultural Gazette of Southern Russia). Nos. 13-14 and 15, pp. 4-5; 4-5. Kharkov, 

 April, 1 91 6. 



In the study of the problem of the phosphoric acid of the soil, the question 

 of the forms in which it occurs is fundamental, and by a knowledge of them " 

 we may attain to a solution of the important problem of the dynamics of 

 soluble phosphoric acid in the soil in relation to the cultivable conditions 

 of this latter. Starting out from this idea, the above writer, together with 

 J. J. Stozkij and P. P. Gretchianinov, conducted experiments with a 

 view to determining the quantity of organic phosphoric acid contained in 

 " podzol " and " tchernoziom " earths. 



The investigators adopted the following method of separation, which 

 perfectly well answers the purpose, as was shown by 2 years of work ; the 

 earth, first washed with 3 % hydrochloric acid, is afterwards treated with 

 a 3 % solution of ammonia. The resulting solution is passed through po- 

 rous filters, and the filtrate precipitated with acetate of lead. The preci- 

 pitate is carefull}^ washed, treated with sulphuretted hydrogen to elimi- 

 nate the lead, and dissolved again in dilute ammonia. It is then filtered, 

 the filtrate is concentrated and afterwards treated with ether, which se- 

 parates the organic combination of phosphorus which it is proposed to study 

 from the mineral phosphoric compound which might be present. 



The soils used for these experiments were : " Podzol " from the farm 

 of the Agronomic Institute of Moscow, with an average of 0.0532 "{, of phos- 

 phoric acid ; the " tchernoziom " of the government of Kursk, with an 

 average of o.iio % ; and " tchernoziom " of the government of Ufa, with 

 an average of 0.145 %. The ammoniacal solutions contained respectively : 

 52.7, 55.18 and 30.41 % of the total phosphoric acid of these earths, in other 

 words, about one half in the case of the first two, and one third in the last. 



