ISSN:0022-5142    

DOI:10.1002/jsfa.2740030901

出版商:John Wiley&Sons, Ltd    

年代:1952

数据来源: WILEY

摘要:

AbstractA rapid method for determining the base‐exchange capacity of soils is described, using a cupric acetate‐acetic acid reagent. The method is applicable to unsaturated and calcareous soils; it gives results very similar to those obtained by the ammonium acetate method, and takes only a fraction of the t

ISSN:0022-5142    

DOI:10.1002/jsfa.2740030902

出版商:John Wiley&Sons, Ltd    

年代:1952

数据来源: WILEY

摘要:

AbstractA photometric procedure based on the reaction between bromides and sodium gold chloride has been developed as another means of determining the bromide formed in the determination of fumigants, such as methyl bromide, and ethylene dibromide, by catalytic oxidation of the gas and its subsequent absorption in an alkaline solution containing hydrogen peroxide. The method is applicable to solutions containing 0.1–4.0 mg. of inorganic bromide in a volume of 8 ml. Extinctions are measured by means of a Spekker photoelectric absorptiometer. Results obtained in a series of experiments with ethylene dibromide are given, and compared with a similar series in which the bromide formed was determined by potentiometric titration with silver nitrat

ISSN:0022-5142    

DOI:10.1002/jsfa.2740030903

出版商:John Wiley&Sons, Ltd    

年代:1952

数据来源: WILEY

摘要:

AbstractAn aqueous‐alcoholic extract of fresh haddock muscle has been fractionated by displacement chromatography using ion‐exchange resins. Twenty‐five amino‐acids and nitrogenous bases have been identified and two of them, trimethylamine oxide and anserine, have been isolated in 5–10 g.

ISSN:0022-5142    

DOI:10.1002/jsfa.2740030904

出版商:John Wiley&Sons, Ltd    

年代:1952

数据来源: WILEY

摘要:

AbstractThe procedures commonly employed for the determination of lignin in plant materials used as animal feeding‐stuffs are reviewed with particular reference to the possible sources of error. A study of the reproducibility of each stage in the determination of lignin by a method employing 72% sulphuric acid is reported, and it is concluded that the variability of the final lignin yields is partly due to the presence of alcohol‐soluble substances not completely removed before the main treatment with 72% sulphuric acid. The need is indicated for further investigation of various ‘humin’ precipitates obtained during lignin determ

ISSN:0022-5142    

DOI:10.1002/jsfa.2740030905

出版商:John Wiley&Sons, Ltd    

年代:1952

数据来源: WILEY

摘要:

AbstractExamination of humin residues obtained at various stages during lignin determination and of the alcohol‐soluble fraction of pre‐treated food materials has indicated the necessity for modifying the procedures used in lignin determination. Factors affecting the dispersion and hydrolysis of cellulose are reported, and it is shown that in order to determine as lignin only material insoluble in concentrated acid it is necessary to filter without dilution after the main treatment. A method for determining ‘acid‐insoluble lignin’ is proposed and shown to give satisfactory agreement between r

ISSN:0022-5142    

DOI:10.1002/jsfa.2740030906

出版商:John Wiley&Sons, Ltd    

年代:1952

数据来源: WILEY

摘要:

Abstract‘Pyrethrins’ I and II have been separated on both alumina and silica columns. On alumina columns there is some evidence of the separation of the cinerins from the pyrethrins.Material separated in this way has been used to elucidate separations obtained by chromatography of pyrethrum extracts on paper impregnated with alumina and by paper chromatography of 2: 4‐dinitrophenylhydrazine derivatives of the ‘pyret

ISSN:0022-5142    

DOI:10.1002/jsfa.2740030907

出版商:John Wiley&Sons, Ltd    

年代:1952

数据来源: WILEY

摘要:

Abstract1. Investigations of the influences of soil cultivation on the growth and yield of winter wheat were carried on at six farms in the Midlothians, Scotland, during the three years 1945–46, 1946–47 and 1947–48.The effects of cultivation treatments on the yields of winter wheat varied with soil type and level of fertility (nutrient status and physical condition). In rich soils, the method of cultivation had little effect on the yield; in the poorer soils yields were reduced if the cultivator was used instead of the plough.2. Of the two types of tillage with a cultivator, i.e. deep and shallow cultivation, the 4‐in. treatment compared more favourably with ploughing as regards crop growth and yield than did the 2‐in. cultivation. In rich soils, the cultivator, working to a depth of 4‐in., could replace the plough for the preparation of seed bed for wheat. In neither season and on neither soil did 2‐in. cultivation compare in growth and yield with ploughing.3. Depth of cultivation had no effect on the date of maturity of the wheat crop nor on the straw

ISSN:0022-5142    

DOI:10.1002/jsfa.2740030908

出版商:John Wiley&Sons, Ltd    

年代:1952

数据来源: WILEY