RECENT WORK l\ AGRICULTURAL SCIENCE. 



AGRICULTURAL CHEMISTRY. 



Agricultural chemistry during- the first half of the year 1905, W. Ziel- 

 8TORFF i Chem. Ztschr., 4 I 1905), Nos. : I , pp. 491-495; .'.. pp. 505 507). This article 

 notes especially the work of Konig, showing the importance of physical factors in 

 soil fertility; of Lemmermann on the relation of volume <>t' soil to plant growth; of 

 Ewerl on the influence of light and copper-lime solutions on metabolism in plant-; 



of Sjollema on the isolati f the colloid substances of soils and the use <>f coloring 



matters in soil investigations; of von Seelhorsl on the influence of soil moisture on 

 the growth of oats; of Loewet al. on the linn ■ requirements of plant.-; of Meyer on the 

 injurious effect of gypsum on plants grown in zinc pots; of Weitz on the use of nitrate 

 of soda as a fertilizer: of Frank, Rosier, Lohnis, and Tacke on the use of lime nitro- 

 gen as a fertilizer; and of von Lepel on the preparation of nitrites and nitrates by 

 electrical discharges and on the use of the product as a fertilizer. 



A number of minor articles are also referred to on experiments with fertilizers of 

 various kinds, including lime, marl, magnesia, steamed Thomas slag, Peruvian guano. 

 ammoniated superphosphate, Thomas-ammonium-phosphate lime, etc. Recent inves- 

 tigations relating to animal nutrition are also reviewed .Most of the articles men 

 tioned have been noted from time to time in this journal. 



Formation of oceanic salt deposits. XLIII, Calcium content of the con- 

 stant solutions at 25°, J. II. van't Hoff and W. C. Blasdale (Sitzber. K Preuss. 

 Akad. Wis8., 1905, No. $4, pp. 712-714; abs. in Jour. Chem. Soc. [Londo 1.88(1905) 

 No. ~>16, II, p. 641).— "This paper concludes the investigation in < ... as calcium 

 compounds at 25° are concerned, and the composition of all constant so.; it ion-, when 

 saturated with the particular calcium salt with which the solutions an' in equilib- 

 rium, is tabulated. For the sake of simplicity, gypsum, glauborite, and syngenite 

 are the only salts taken into consideration, hut the quantities of calcium found in the 

 solutions can not, however, on this account differ appreciably from the true equilib- 

 rium values."' 



Comparative study of methods of analysis of fertilizers in different coun- 

 tries, L. Sicard (.1////. Ecole Nat. Agr. Wontpellier, n. ser., No. ?, /</>. 111- 

 147). — This is the second part of a report <»n this subject dealing with methods of 

 determining phosphoric acid. 



A method for the determination of black alkali in irrigating waters and 

 soil extracts, W. \V. Skinneb (.I<>ur. Amer. Chem. S . .V". /,/'/'. 77- 



80). — The method described for this purpose is a modification and adaptation of the 

 method proposed by Hehner as a substitute for the Clark process for determining 

 hardness of waters. 



Two hundred re. of the water or soil solution is evaporated to dryness in a plati- 

 num or silver dish, with 50 to 150 ee. of fiftieth-normal -odium carbonate solution. 

 The residue is rubbed up with distilled water free from carbon diozid, the volume 

 being made up to 100 cc. Fifty cc. of this solution, which has been allowed to stand 

 until it is clear, is titrated with fiftieth-normal sulphuric acid, adding 5 cc of chloro- 

 form and 1 cc. erythrosin as indicator. 



633 



