CHEMISTRY. 10-t3 



The determination of nitrogen in nitrates and nitric-acid esters, A. Wohl 



and (). PopPExiJEKc ( Iler. Dent. Chcnt. (icselL, M {lUO-i), pp. 67r>-GS4; uhs. in Chem. 

 Centhl, 1903, 1, No. 15, p. S9J; Jour. Chem. Soc. London, S4{190.J),No. 486, II, p.328).— 

 Nitrogen is determined by decomposing the substance with sulphuric acid and mercury 

 in an exhausted flask, which is thoroughly shaken until the substance is completely 

 dissolved, the pressure in the flask, then being determined by means of a manometer. 

 The most serious source of error, the possible formation of oximes, is overcome by 

 adding chromic acid to the sulphuri(^ acid. Various cujrrections wluch should be 

 applied are given. 



On tlie determination of organic nitrogen in the presence of nitric nitro- 

 gen, A. QiAKTAKo].! {Staz. SiK'i-. A'jr. Ihil, .16 {lUO.l), Xo. 1, pp. 47-'>l).—ln the 

 method proposed 1 gm. of substance is treated with 10 cc. of formic acid in a flask 

 and 5 cc. of concentrated sulphuric acid is slowly added in the cold with constant 

 stirring, the operation being continued in a Kchultze-Tieinatm apparatus in the 

 usual way. 



A burette and standard solutions convenient for the determination of 

 nitrogen^-by the Kjeldahl method, A. W. Boswokth {.fnur. Amer. Chem. >S'oc., 25 

 {190.1), No. 5, pp. 535-537). — Using 1 gm. of substance for the determination, the 

 distillate is collected in 8 cc. of i-normal sulphuric or hydrochloiic acid. This is 

 titrated with 14.04-normal alkali, which is run in from a burette graduated in reverse 

 order; that is, the zero point is the lowest mark. This burette is fllled at the l)egin- 

 ning to the 56.16 cc. jiiark, and the readings give percentages of nitrogen multiplied 

 by 10. 



The estimation of small amounts of carbon monoxid in the air, Spitt.v 

 {Arcli. Ilyg., 40 {1903), No. 3, pp. 284-310, fig. 1). — The method proposed depends 

 upon the oxidation of the carbon monoxid to dioxid in thi^ jiresence of added 

 hydrogen, by means of palladium heated by an electric current. 



The distribution of arsenic in nature, F. G.\rku;ou {Compf. licnd. Acad. Sci. 

 Pari.% 135 {1902), No. 24, pp. 1113-1115). 



The determination of sulphur in plants, G. S. Fk.\ps {North Carolina Sla. Rpt. 

 1902, pp. 42, .;;.}).— Since this article was originally published (E. S. R., 13, p. 916) 

 it has l)een found more satisfactory, as stated in a note, to substitute cahuum acetate 

 for potassium nitrate in the preparation of the ash. 



The determination of sulphur and chlorin in plants, G. S. Fraps [NorUi Car- 

 olina ,S'/«. Rpt. 1902, pp. 44-49). — This is a less detailed account of the work pre- 

 sented before the Association of Official Agricultural Chemists in 1902 (E. S. R., 14, 

 p. 114), the results of which were in favor of the nitric acid method, modified by 

 the substitution of calcium acetate for ixiLussium nitrate for the determination of 

 total sulphur, and the method of ignition with sodium carbonate for the determina- 

 tion of chlorin, as compared with several other methods. 



The sulphur content of some vegetable materials, W. A. Witiikks and (t. S. 

 Fkaps {North Carolina Sta. Rpt. 1902, pp. ,«-.56').— Determinations of the sulphur 

 content of a number of vegetable materials are reported. The authors found that 

 the ash of plants contains only a portion of the total sulphur. The ash of cotton- 

 seed meal was found to contain 1/6, cotton-seed hulls 1/5, oats 1/10, cowpeas 1/6, corn. 

 1/50, peanuts 1/3, and tobacco 4y5 of the total sulphur. The sulphur content was 

 found to be greater than has usually been considered. The sulphur content of an 

 ash is considered no indication of the amount of sulphur in the plant, and conclu- 

 sions reached by ash analyses as regards the sulphur content of the plant are there- 

 fore considered entirely valueless. 



The determination of pentosan-free crude fiber, G. S. I-'kaps {Xorlli Carolina 

 8ta. Rpt. 1902, pp. 59-62).— This paper was presented before the Association of 

 Ofiicial Agricultural Chemists in 1901 (E. S. R., 13, p. 410). The results of tests 



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