312 EXPERIMENT STATION RECORD. [Vol. 43 



The best results were obtained by the following method : " One hundred ftnis. 

 of finely pulverized soil was agitated in a mechanical shaker for five minutes 

 and clarified either by the use of 2 gm. of alum or by the Pasteur-Chamherlaiid 

 filter ; 20-cc. portions were pipetted into ground-glass-stoppered bottles and an 

 excess of 0.1/n silver nitrate added; 10 cc. of 95 per cent ethyl alcohol wa>< 

 added, and the mixture shaken until the silver chlorid was coagulated and the 

 supernatant solution was clear; 2 cc. of ferric sulphate solution containing 20 

 gra. of ferric sulphate to 500 cc. of water and 5 cc. of dilute nitric acid were 

 added ; the excess of silver nitrate was then titrated by the use of 0.1/n 

 NH4CNS." 



Concerning the effect of heat on the reaction between lime-water and 

 acid soils, II. H. Robinson {Soil ScL, 9 {1920), No. 2, pp. 151-157).— Results 

 obtaineil by a study of the Veitch lime-water method for determining soil 

 acidity, as conducted at the Oregon Experiment Station, are reported. 



It was found that the lime requirement of the soil as shown by the lime-water 

 method indicates a reaction that takes place under the conditions performed, 

 and that the results will be affected by any variation of the following factors : 

 (1) The physical or chemical properties of the soil, (2) probably by the ratio 

 of amount of soil to quantity of solutions to be evaporated, (3) the tempeni- 

 ture at which evaporation is made, (4) continued heating after the soil has 

 been dehydrated, (5) the length of time during which treated and dried soil 

 remains in contact with water, and (6) the source of heat, namely, steam bath, 

 sand bath, hot plate, etc. Results will be comparative when the lime-water 

 method is used if the determinations are conducted in exactly the same man- 

 ner. The data are thought to emphasize the necessity of controlling all in- 

 fluencing factors if the lime-water method is used to observe changes in a soil 

 by comparison of results obtained at different times. 



Methods for the determination of borax in fertilizers and fertilizer 

 materials, W. H. Ross and R. B. Deemer {Aiuer. Fert., 52 {1920), No. 6, pp. 

 62-64). — This is a revision of the methods previously noted (E. S. R., 42, p. 

 313), a few minor changes having been made as an outcome of further work on 

 the subject. 



Qualitative method for the detection of borax in mixed fertilizers, AV. R. 

 Pope and W. H. Ross {Amer. Fert., 52 {1920), No. 6, pp. 65, 66).— This quali- 

 tative method for detecting borax in mixed fertilizers, which has been de- 

 veloped at the Bureau of Soils, U. S. Department of Agriculture, is recom- 

 mended particularly for use in eliminating fertilizer samples which contain 

 distinctly less than 0.1 per cent of borax. The method is as follows: 



Weigh 2 gm. of the powdered sample into a small flask, mix with 2 cc. of 

 water and 48 cc. of 95 per cent alcohol, shake thoroughly, and filter. Transfer 

 a 5 cc. portion of the filtrate to a small porcelain evaporating dish, add one 

 drop of a 1 per cent solution of phenolphthalein in alcohol, and just enough 

 approximately n/2 NaOH to make the solution alkaline, avoiding an excess. 

 Evaporate to dryness on a steam bath, ignite below redness until the organic 

 matter is fully carbonized, and treat the ignited residue with 0.5 cc. of ap- 

 proximately n/2 PICl and about 10 cc. of hot water. Filter if necessary into a 

 small porcelain evaporating dish, wash two or three times with hot water, and 

 bring the volume of the titrate to about 25 cc. Add to the solution 1 cc. of a 1 

 per cent solution of turmeric in alcohol, stir, and evaporate to dryness on a 

 steam bath. A pink coloration which turns olive green on the addition of 

 KaOH confirms the presence of borax. If this is matched against a standard 

 solution of boric acid treated in the same way with the use of tincture of 

 curcumin instead of turmeric, it is possible to determine whether the borax in 

 the sample is more or less than 0.1 per cent. 



