SOILS FERTILIZERS. 419 



to contain about 1 per cent of potash, 0.65 per cent of i)hosphoric acid, and 0.44 

 per cent of nitrojien (O.IS i)er cent in form of nitric nitroj^en). 



On the composition of the ashes and lapilli ejected by Vesuvius during 

 the period of activity in April, 1906, N. Passerini {Atti R. Accad. Econ. Af/r. 

 (Icorp. Fircnzc, 5. scr., 3 {I90(!). Xo. '/, pp. 374~385). — Analyses of a number of 

 different samples are reported and discussed with reference to similar studies 

 of otiier investiiiators. 



Report on progress in geological peat and moor investigations during 

 1905 (Jahnshcr. K. Uiif/ar. (hoi. A)i>^t., 1905. pp. 2'f8-272. pi. /).— The report 

 deals with the occurrence, conijiosition, etc., of Hungarian deposits. 



The utilization of peat land on the Continent {Jour. Bd. Agr. [London]. 

 I'l (1907), No. 3, pp. 146-155). — Information is given in some detail regai-ding 

 the classification, composition, and utilization for agricultural and industrial 

 purposes of peat lands, compiled largely from articles in various German jour- 

 nals. 



Results of chemical investigations on a series of moor soils from north- 

 west Germany, B. Tacke and A. Spiecker (Ztsehr. Forst it. Jagdw.. 39 {1907), 

 X<>. '/. pp. 2 13-229). — The results of a somewhat detailed chemical study of a 

 large number of samples of moor soils are reported. 



The mineral constituents of the soil solutions, F. K. Cameron and J. yi. 

 Bell {Arm. Ecolc Nat. Agr. MontpclUcr. n. scr., 6 {1907), Nos. 3, pp. 182-21t0, 

 figs. 3; .'/, pp. 2-^1-267, fig. 1). — This is a reprint of Bulletin 30 of the Bureau of 

 Soils of this Department (E. S. R., 17, p. 742). 



Studies on humus formation, II, S. Suzuki {Bui. Col. Agr., Tokgo Imp. 

 Unir., 7 (1907). No. 3. pp. .'il9-Ji23). — A continuation of previous investigations 

 (E. S. K., IS. p. 14) is reported in which it was found that ])rotein, starch, and 

 p(>nto.sau,s, but not fat or cellulose, can produce the black matter of humus and 

 that the restriction of air Is very essential to humus formation. An examination 

 of 2 samples of humus showed that the nitrogen was in the form of protein. 



Organic nitrogen in Hawaiian soils, E. C. Shorey {Hawaii Sta. Rpt. 1906, 

 pp. .17-59, pi. 1). — This article states briefly the present status of the nitrogen 

 problem as related to agriculture, calls attention to the high content of nitrogen 

 in Hawaiian soils, reviews our present knowledge of soil nitrogen, and gives a 

 ]>reliminary report on studies of the nitrogenous compounds in Hawaiian soils, 

 including solubility of the nitrogeiious compounds in various solvents, the am- 

 monia lu'oduced on distillation with various basic substances, and the character 

 of the decomposition products of the nitrogenous matter of the soil. 



By extraction of a soil rich in nitrogen (0.73 per cent) with 5-per cent caustic 

 soda, i)recipitating with nitric acid, removing the precipitate, neutralizing the 

 filtrate with soda, and again filtering, there was obtained a neutral filtrate which 

 on concentratitm to small bulk yielded a small amount of dark flocculent, appar- 

 ently humin, substance. The filtrate from this on precipitation with silver 

 nitrate or lead acetate and decomi)osition of the precipitate with hydrogen sul- 

 pliid gave on c<mcentration a small amount of a soluble crystalline substance 

 which was subsequently demonstrated to be picolin carboxylic acid. The occur- 

 rence of this substance in Hawaiian soils is taken to indicate the presence of 

 pyridin compounds, which may exert a poisonous effect upon plants grown on 

 the soils. 



Nitrifying power of chernozem soils, influence of various factors on it, 

 and quantity of nitrates in the soil at different seasons of the year, V. Saz- 

 anov {Zhur. Opuitn. Agroii. \Rusn. .Jour. E.rpt. Lnndir.]. 8 {1907), No. 1, pp. 

 1-38). — Russian chernozem soils respond readily to application of superphos- 

 phate, but have little or no need of nitrogenous fertilizers. In the spring, how- 



