1917] AGRICULTURAL CHEMISTRY — AGROTECHNY. 15 



95 per cent alcohol added, with constant stirring, and allowed to stand from 

 4 to 18 hours. The precipitate is then filtered and washed a few times with 

 1 per cent ammonium oxalate solution, several times with 1 per cent of am- 

 monium oxalate containing 20 per cent by volume of alcohol, and, finally, a few 

 times with water containing 20 per cent by volume of alcohol. The precipitate 

 is burned to the oxid, dissolved in nitric acid, dehydrated, the calcium nitrate 

 separated from the strontium nitrate by means of absolute alcohol and ether, 

 and each element then determined in the u.sual manner. 



Analytical data submitted show the accuracy of the modified procedui*e. 



A table for values of carbon in carbon dioxid, H. Loomis {Jour. Indus, and 

 Engin. Cliem., 8 (1916), No. 7, p. 637). — A table corrected for aqueous vapor, 

 ranging from 700 to 718 mm. pressure, and from a temperature of 10 to 30° C, 

 is submitted. 



A rapid method for the accurate determination of total carbon in soils, 

 R. M. Saltek (Jour. Indus, and Engin. Chcm., 8 (1916), No. 7, pp. 637-639, fig. 

 1). — A method which has been successfully used at the West Virginia Experi- 

 ment Station, and which depends on the direct combustion of the soil in a cur- 

 rent of oxygen, drying the gases by phosphorus pentoiid, and subsequently ab- 

 sorbing the carbon dioxid in soda-lime, is described in detail. It is an adapta- 

 tion with modifications of the method described by Fleming ^ for the rapid de- 

 termination of carbon in iron and steel. 



The reducing- action of distillates from certain carbohydrates on distilla- 

 tion with steam and from alkaline solution, J. P. Atkinson (Collected Studies 

 Bur. Lab. Dept. Health N. Y. City, 8 (191^-15), pp. 227-229).— In the examina- 

 tion of a sample of water extraordinarily high figures for free ammonia with 

 Nessler's reagent were obtained. On further examination the water was found 

 to contain a reducing sugar. Subsequent experiments with saccharose, lactose, 

 glucose, levulose, maltose, mannose, dextrin, soluble starch, and filter paper 

 showed that these substances may have an influence on the depth of color in 

 ammonia readings, especially in the examination of surface waters which are 

 likely to be contaminated Avith organic matter. 



The rate of ammonia distillation from water, F. W. Bbuckmillee {Jour. 

 Indus, and Engin. Chern., 8 {1916), No. 7, pp. 602, 603).— From a study of the 

 rate of ammonia distillation the author concludes that suflicient information 

 upon which to base a judgment as to the pollution of a water can be obtained, in 

 ordinary routine water analysis, by nesslerizing three 50-cc. portions of the 

 distillate for free ammonia, and four 50-cc. portions for albuminoid ammonia. 



Melting-point determination of fats and waxes, L. Golouetz {Chem. Ztg., 

 JiO (1916), No. 31-32, p. 228, fig. i).— An apparatus in which a small, closely 

 fitting glass tube about 3.5 cm. long and sealed at one end is placed over the 

 end of the thermometer in melting-point determinations is described. 



In making a determination the sample (about 0.2 gm.) is placed in this small 

 rube, gently heated, the thermometer rapidly inserted, and placed in a small 

 vial fitted with a suitable stopper. The mercury column is then closely observed 

 and the point at which the first faint turbidity is noticed taken as the melting 

 point. The advantages claimed for the method are constancy in the results of 

 the determinations ; the accuracy of the temperature readings, as the whole 

 apparatus can be conveniently placed on a level with the eye; the facts that 

 only small amounts of material are required, and that these can be used for 

 other determinations if necessary ; repeated determinations with the same 

 sample ; the rapidity of the procedure ; and the simplicity of the apparatus. 



» Iron Age, 93 (1914), No. 1, pp. 64-66. 



