1052 EXPERIMENT STATION RECORD. 



A short method for the determination of potash in soils, potash salts, and 

 similar compounds, J. IIasenhaumku {('Iwiii. /J(/., 2H {1904), \n. JS, ]>p. 210, 

 211). — lu tlu' inetlidd projKjsed the liydrocliloric-acid solution < if the soil is evapo- 

 rated to dryness in ii porcelain dish, taken np in water, and transferred to a platinum 

 dish. Annnonia and anunoniuni carl ;onate are added and the soliuion evaporated 

 to dryness. The residue is heated gently over a j;as burner until the anunoniuni 

 salts are driven off and the organic, matter destroyed. The residue is treated for a 

 short while with hot water, the solution filtered, and after acidilication of the filtrate 

 with hydrochloric acid, the potash is precipitated with perchloric acid or platinum 

 chlorid. 



Satisfactory tests of the method are reported. Tiie ()l)ject of evaporatinjr to dry- 

 ness and heating after the addition of ammonia and aiiiUKiniuiii cailionatc is to 

 destroy the power of the bulky precipitate to occlude potasii, as first pointeil out by 

 J. Konig. 



On the determination of the available amounts of lime and magnesia in 

 the soil, T. Katayama {Bid. Col. Agr., Tukijo Imp. Univ., {l!i()4), No. 2, }>]>. lOS- 

 124, pl-'i- 2)- — A series of pot experiments with onions grown in sandy and loamy 

 soils containing different proportions of lime and magnesia are reported. The avail- 

 able lime and magnesia in the soils were determined by extracting the fine earth 

 (particles less than 0.25 mm. in diameter) for 50 minutes with boiling 10 per cent 

 hydrochloric acid in the proportion of 50 cc. of acid to 25 gni. of soil. Check experi- 

 ments with sand cultures were also made. 



"Sand culture, as well as the cultures in two soils differing widely in character fnjm 

 each other, yielded the best results when the availaljle amounts of lime and magnesia 

 were present in the ratio 2 : 1 ; in other words, the onion has the lime factor 2. Lime 

 and magnesia in the sand culture were added in form of solutions, hence the total 

 amount of these salts were easily available, even if precipitated as finely divided phos- 

 phates. As to the soil culture the 'available amounts ' of lime and magnesia were deter- 

 mined accordmg to my modification of the usual method and their ratios changed by 

 adding carbonate of lime in such quantities as to reach the fixed ratios of the sand 



CaO "^ 



culture. Since in all my experiments of 1902 and 1903 the ratio ,r^i-— r=" proved the 

 •^ '■ MgO 1 



most favorable for the onion plant, the determination of the available amounts must 



have been made by a reliable method." 



The determination of sodium perchlorate in commercial sodium nitrate, 

 H. Lemaitre {Mouit. ,'Sci., 4- «'r., LS [1004), p. 353; oi.s'. hi Chan. Zlg., :?<5" (1904), ^"0. 

 31, Repert. No. 8, p. 106") .—With nitrate containing less than 4 per cent of perchlo- 

 rate 5 gm. of the material is mixed with 3 gm. of pure dry sodium sulphite. The 

 mixture is fused in a platinum dish, cooled, and taken up in water. The solution is 

 heated to boiling and 200 cc. of a boiling 4 per cent barium nitrate solution is added. 

 The precipitate is allowed to settle and the solution filtered. Eight and two-tenths 

 cubic centimetei's of approximately normal soda solution and 1.2 gm. (if sodium 

 piersulphate are added and the solution boiled and filtered. The filtrate with the 

 wash water is exactly neutralized with a weak acetic-acid solution, using phenoi)litha- 

 lein as indicator, and titrated with tenth-normal silver nitrate, using potassium 

 chromate as indicator to determine chlorin, or the chlorin may be determined 

 gravimetrically. The treatment with sodium sulphite converts the chlorates and 

 iodates into chlorids and iodids. 



Comparison of methods for the quantitative determination of nitric acid in 

 water, A. F. Dokatscmia.iew ( Vrach [<SV. Petersburg], 1904, P- 26; abs. in Chem. Zlg., 

 SS {1904), No. 17, Repert. No. 4, p. 54).— A comparison of the methods of Schultze- 

 Tiemann, Noll, Grandval-Lajoux, Kostjamin, and Marx-Trommsdorff is reported. 

 The most uniform and exact results were obtained by the first method. 



