418 EXPERIMENT STATION RECORD. 



"In the determination of phosphorus practically identical results were obtained 

 ■whether the material was oxidized by combustion in oxygen, by heating with car- 

 bonaie and nitrate, or by boiling with sulphuric acid and ammonium nitrate. For 

 the analysis of food materials and physiological products the last-mentioned method 

 will probably be found most convenient, especially in laboratories where the Kjeldahl 

 nietho<l for nitrogen is largely used. 



"In analyzing animal and vegetable materials there is very much greater danger 

 of loss by volatilization of sulphur than of phosphorus." 



The estimation of soil acidity and the lime requirements of soils, F. P. 

 Veitch {Jour. Amer. Chem. Soc, ii4 {1902), No. 11, pp. 11 SO- 11 28) .—The method 

 proposed is as follows: 



"For the preliminary test, to ?. portions of 10 gm. each of the soil in platinum 

 dishes add 50 to 60 cc. of distilled water, and different amounts of standard lime- 

 water. For example, to the first 10 cc, to the second 20 cc, and to the third 30 cc. 

 of limewater are added. Dry down at once on the steam bath, transfer to a stop- 

 pered Jena flask with 100 cc. of distilled water, allow to stand overnight, with 

 occasional shaking, filter (the filtrate should be clear or Init faintly turbid), take 50 

 cc. in a Jena beaker, add a few drops of phenolphthalein solution, and boil until the 

 appearance of the pink color or, in the case where no color is developed, to a volume 

 of about 5 cc. Then with the 2 portions of treated soil, one of which has been ren- 

 dered alkaline by the added limewater and the other of which is still acid, as guides, 

 prepare 3 fresh portions of 10 gm. each, and add limewater as before, except that 

 the amount added to a dish differs from that added to another, by only 1 or 2 cc. 

 Dry, allow to stand, filter, and treat exactly as before. The smallest amount of 

 limewater which gives the characteristic pink with phenolphthalein is taken as the 

 acidity equivalent of the soil. From the data thus obtained, the acidity and lime 

 requirements of the soil may be calculated." 



The results obtained with this method on a number of samples of soils from dif- 

 ferent localities are compared with those obtained by Wheeler in field and labora- 

 tory experiments on the same soils, but no very definite relation is shown between 

 the lime requirements as indicated by the proposed method and the productive 

 capacity of the soils. The relations of soil acidity to the productive power are 

 discussed, the need of further study of the subject being pointed out. 



Tacke's method for determining' acidity in peat soils as applied to other 

 soils, M. Gratchev {ZItur. Opuiln. Agron. [Jour. E.ipt. Laiichr.~\, S {1902), No. 3, 

 pp. 355-365). — This method (E. S. R., 9., p. 32) is not considered applicable to soils 

 in general. 



A short method of determining potash, B. Sjollema {Cliem. Ztg., 26 {1902), 

 No. 85, pp. 1014, 1015). — The use of barium carbonate and magnesium chlorid to 

 replace barium chlorid in the precipitation of sulphates in case of potash salts is 

 proposed. The carbonate (stirred up in water) is used at the rate of 10 gm. of car- 

 bonate to 5 gm. of the potash salt. In case of salts containing consideral)le amounts 

 of chlorids the use of magnesium chlorid is unnecessary. 



The volumetric determination of lime in the presence of salts of iron, alu- 

 minum, manganese, magnesium, phosphoric acid, and sulphuric acid, N. 

 STEPANOv(Z/tMr. Opuitn. Agron. [Jour. Expt. Landw.'], 3 {1902), No. 2, pp. 190-200). — 

 In the method proposed the lime in 50 cc. of the solution to be examined, corre- 

 sponding to 2.5 gm. of substance, is precipitated by adding ammonium oxalate in 

 presence of a slight excess of oxalic acid. The precipitate is washed free from oxalic 

 acid, dissolved in 10 per cent hydrochloric acid, and titrated with potassium per- 

 manganate solution. 



The separation of iron, aluminum, and phosphoric acid from lime, N. 

 Stepanov {Zlmr. Opuitn. Agrou. \_Jour. E.rpt. Landw.l, 3 {1902), No. 2, pp. 201-203).— 

 The results reported show that 2 precipitations with ammonia in presence of acetic 

 acid are not sufficient to entirely free the precipitate from lime. 



