AGRICULTURAL CHEMISTRY — AGROTECHNY. 616 



Determination of nitrogenous constituents in raw rubber, A. Tschirch 

 and W. Sghmitz {Giunmi Zty., 26 {1912), No. 52, pp. 2079-2081; abs. in Jour. 

 Soc. Ghem. Indus., 31 {1912), No. 21, p. 10Jf2). — As a solvent for rubber pen- 

 tachloroetban (boiling point 159° C). tetracbloroetbau, and percbloroetbylen 

 are recommended. 



"Two and five-tentb gm. of raw Para (not wasbed or deresinified) was dried 

 for eigbt days in vacuo and placed in a 500 cc. Erlenmeyer flask with 40 to GO 

 CO. of pentachloroetbau ; cotton wool was placed in tbe neck. Tbe flask was 

 heated for 4 to 6 hours at 80° C. till all the rubber had dissolved. After cooling, 

 the liquid was highly diluted with chloroform (about 400 cc.) and allowed to 

 settle in a separating funnel. The precipitate was collected on an ordinary 

 paper filter. Warning is given as to the use of a centrifuge. The residue on the 

 filter was extracted with chloroform in a Soxhlet apparatus, dried in vacuo and 

 weighed. The nitrogen was then determined by the K^jeldahl method. The 

 protein contained 12 to 14 per cent of nitrogen. Ray Para contained 2.9 to 3.1 

 per cent of residue (11 to 12.G per cent of nitrogen). Nearly all this nitrogen 

 was found in the insoluble residue, in which, allowing for ash, the nitrogen was 

 from 14 to 15.6 per cent. Preliminary experiments on the nature of the protein 

 are described ; it does not appear to be a true protein." 



Industrial hygiene of leather manufacture, with especial reference to 

 the industry in Baden, F. Holtzmann {Gewerhehygiene der Lederfabrilcation 

 mit besondcrer Beriicksichtigung der badischcn Industrie. Inaug. Diss., Tech. 

 Hochsch. Karlsruhe, 1912, pp. 28). — This discusses the various stages of leather 

 manufacture, their significance from a hygienic standpoint, anthrax in tanneries, 

 and the healthfulness of leather workers in general. A bibliography comprising 

 34 titles is appended. 



Preparation of tanning and coloring extracts, G. Gbasser {Ghem. Ztg., 37 

 (1913), No. 37, pp. 373-375). — This gives a short description of the technical 

 processes used for preparing tanbark extracts and commercial vegetable coloring 

 matters. 



The hydrolysis of cellulose, I, R. Willstatteb and L. Zechmeister {Ber. 

 Deut. Ghem. Gesell., 46 {1913), No. 11, pp. 2401-2412, fig. 1; abs. in Nature 

 [London], 92 {191S), No. 2291, pp. 107, 108).— This is carried out by treating 

 the cellulose with coW, fuming hydrochloric acid of a specific gravity of 1.204 to 

 1.212 and which contains from 40 to 41.4 per cent of hydrogen chlorid. The 

 cellulose (cotton or filter paper), after being treated, will show within 24 to 

 48 hours a conversion of about 95 to 96 per cent of the theoretical quantity of 

 dextrose. Ordinary hydrochloric acid, which contains only 37.6 per cent of 

 hydrogen chlorid, does not decompose cellulose to this extent but merely dis- 

 integrates the fiber and causes gelatin ization. 



" One of the most striking observations recorded in the paper is the very 

 high specific rotation shown by dextrose when dissolved in concentrated hydro- 

 chloric acid. In 41.4 per cent hydrochloric acid [a]D at 16° C. was found to be 

 106°, which approximates to that of the so-called a form of dextrose (110°), the 

 ordinary value observed in aqueous solution for the equilibrium mixture of a 

 and /3 forms being 52.5°. In 44.5 per cent hydrochloric acid, however, the 

 extraordinarily high value of 164.6° was observed for [a]D at 5° C." 



Some experiments on the conversion of long-leaf pine to paper pulp by 

 the soda and sulphate processes, S. D. Wells {Jour. Indus, ayid Engin. Ghem., 

 5 (1913), No. 11, pp. 906, 907; abs. in Science, n. ser., 38 {1913), No. 985, p. 

 710). — One hundred and fifty small batches were made in autoclaves for the 

 purpose of studying various factors relative to the cooking process in the sul- 

 phate method. " It was found that the more caustic soda or sodium sulphid in 

 use, the greater the concentration, the higher the temperature and the longer 



