摘要:

ORGANIC ANALYSIS 325 Soluble d i d s ... ... ... Non-thmins . . . ... Tannin ... ... . . I I - 1--- Percent. I Per Cent. Per Cent. 2.76 4-77 25-7 1-89 3.63 13.5 0.86 1-15 12.2 Heartwood. The only part of the wood which 4as any possible value as a souroe of tannin is the heartwood; the chief available raw material would be the sawdust. The tannin imparts a dark purplish-brown colour to the outside of hides, but the leather produced might be satisfaotory as a heavy sole leather.The liquor which oolIects an steam-kilning the wood contains from 7 to 10 per cent. of tannin. W. P. S. Estimation of Thiophene. P. E. Spielmann and S. P. Schotz. (J. Soc. Chem. Id., 1919,38,188-189T.)-The authors have examined various met-hods whioh have been suggested for the estimation of thiophene in benzene, and recommend the following modifioations of the basic mercuric sulphate and acetate methods : Basic Mercu/l.ic Szi,&hate Method.-Two C.C.of the benzene and 20 C.C. basic mercuric sulphate solution (sulphuric acid 20 c.c., water 100 ox., and mercuric oxide 5 grms.) axe shaken in a closed tube for three hours; the white precipitate which is formed is collected, washed with hot water, dried at 110" C., and weighed.The weight multiplied by 0.0757 gives the amount of thiophene in 2 C.C. of benzene. Basic Mercuric Acetate Method.---Ten O.C. of the benzene and 4 grms. of baaic mercuric aaetafe (mercuric oxide, 1 part, glacial aceti0 said, 2 parts, the mixture b~iing filtered and the salt washed with ether) are heated on a water-bath under a, reflux condenser for fifteen minutes ; after cooling, the precipitate i8 collected, washed with water, dried at 100" C., and weighed. The weight is multiplied by 0.07516 to obtain the oorresponding amount of thiophene. w. P. s.

ISSN:0003-2654    

DOI:10.1039/AN923480152b

出版商:RSC    

年代:1923

数据来源: RSC