CHEMISTRY. 



885 



This iiK'thod" is l)rit'iiy outlined us follows: "To a (letlnitt' volume of air, usually 1 

 to 2 liters, is added a measured anK)unt of standard barium hydroxid, care being 

 taken to avoid contaet of the solution with the air. After the al)sorption of the car- 

 bon dioxid the solution is filtered under reduced pressure throut^h asbestos and the 

 clear barium hydroxid received into a known excess of standard hydrochloric acid. 

 The absorption vessel is rinsed out with water free from carl)on dioxid. The excess 

 of acid is then deternuned by titration with barium hydroxid." Keagents and 

 apiianitus required for carrying t)ut the method are described in detail and numerous 

 tests of its accuracy are rejiorted. "The results ol)tained coniirm Walker's statement 

 that the method is accurate under ordinary circumstances to 0.1 part in 10,000. . . . 

 With a Uttle practice the method was found to T)e rapid and easy of execution and 

 preferable to the Pettenkofer method." 



The oxidation of organic nitrog-en compounds and the estimation of the 

 carbon and nitrogen therein by the moist process, K. A'an Aken {Proc. Sec. 

 ScL, Koninkl. Akcul. W'l'tcii.sch. Amdevdiiiii, 4 {1901-k^), pp. 91-05). — Tests are repoi'ted 

 which show that Fritsch's method >> gives too low results in case of certain amids and 

 urea derivatives. This appears to be due largely to the relative proximity of the 

 nitrogen atoms in the compounds. The use of an oxidizing agent like chromic acid 

 in the Kjeldahl jirocess does not obviate the difficulty. 



Report on the determination of constants for use in the preparation of 

 hydrographic tables, M. Knudsen kt al. (A'. JJan.'^ke Vkleusk. iSel.^k. Skr., (J. .srr., 

 IJ (UK).:), Xo. I, pp. 15, figs. 18). — This includes pai>ers on the collection and prepa- 

 ration of water samples, the determination of specific gravity, determination of 

 chlorin and salt, and expansion of sea water. 



On the impurities in compressed oxygen and their role in combustion in 

 the bomb calorimeter, M. Bektuklot [Conipt. RcikJ. Acnd. Sri. J'ari'f, 1,15 [1902), 

 No. 20, pp. 82 1-824)- — The author finds that in the amount of compressed oxygen 

 used for carrying out a combustion with the l)omb calorimeter no carbon dioxid or 

 at least only a negligible quantity is contained. However, the oxygen was found to 

 contain 0.0005 gm. hydrogen, which would by oxidation produce a small (juantity 

 of heat. He believes, therefore, that the quantity of hydrogen mixed witli the 

 oxygen should be determined. 



The nature, determination, and distribution of the pentosans in tho Sea 

 Island cotton, F. S. Shivek {Soiitli Carolina Sta. Bid. 78, pp. 38). — The literature 

 of pentosans and their determination is reviewed at considerable length, the 

 phenylhydrazin and phloroglucin methods of analysis as used by the author are 

 given, and determinations by V)oth methods of the jaentosan content of Sea Island 

 cotton and its parts are reported. The finest and coarsest varieties of cotton of the 

 crops of 1896 and 1898 were used. The following table sunnnarizes the main part 

 of the data: 



PentosariH in Sea Island cotton. 



«Jour. Chem. Soc. [London], 77 (1900), p. 

 l> Liebig's Ann. Chem., 294 (1897), p. 79. 



1110. 



