AGRICULTURAL CHEMISTRY — AGROTECHNY. 413 



p. 957). — The coloration produced by vai-ious reagents is probably due to the 

 presence of a peroxidase which differs from the veg^able peroxidase. The 

 peroxidase does not occur in donkey's milk, and the author consequently con- 

 cludes that the peroxidase in milk can not be considered as originating from 

 the food eaten by the animal. 



Modifications of the Robin process for butter analysis, Marion {Ann. 

 Chim. AnaJyt., 11 {1912), No. 7, pp. 256-25S; ahs. in Jour. Chem. Soc. [Lon- 

 don], 102 (1912), No. 599, II, p. 872).— "It is pointed out how essential it is 

 that in Robin's process [E. S. R., 27, p. 812] the temperature should be constant 

 at 15° C. Moreover, the strength of the alcohol (56.5° French) must be main- 

 tained all through the operation. Starting from absolute alcohol is very incon- 

 venient, but the author gives instructions how to employ such alcohols as are 

 kept in any laboratory and are of a known strength," 



On available sugar and a system of control in the boiling house, N. Deekb 

 {Haicaiian Sugar Planters' Sta., Agr. and Chem. Bui. Jfl, pp. 19). — "A system 

 of control of the boiling house is suggested, based on the formula maximum 



possible yield =?^^^^^, where s, ;, and m are the values of sucrose per cent ^^ ^^^ 



j{s—m) Bnx 



sugars, the juice, and the waste molasses, the ratio being named ' gi*avity 



coefficient ' to distinguish it from the allied ratios, true purity and apparent 



purity. 



"A further control, based on balance sheets of the gravity solids, sucrose, 

 and gravity nonsucrose, is proposed, by gravity solids being meant the solids as 

 deduced from specific gravity, and the gravity nonsucrose being the difference 

 between the gravity solids and the sucrose." 



Chemical technology of fats, oils, waxes, etc., C. Stiepel {Einzelschr. 

 Chem. Tech., 1 {1911), No. S, pp. 249-399, figs. 22).— This is one of a series of 

 books on chemical technology. It deals with the history, methods of obtaining, 

 purification, and use of fats, oils, and waxes. A chapter on glycerol is also 

 included. 



Oils and fats of vegetable origin produced in British India, D. Hooper 

 {Agr. Ledger, 1911-12, No. 5 {Veg. Prod. 8er., No. 116), pp. 107-171).— The 

 object of this publication is to bring together general and technical informa- 

 tion relating to the sources, preparation, use, and value of vegetable fats and 

 oils available in India. 



The hydrogenation of oils, C. Ellis {Jour. Indus, and Engin. Chem', 5 

 {1913), No. 2, pp. 95-106, figs. 27; Chem. Engin., 17 {1913), No. 3, pp. 93-103, 

 figs. 22). — This is a description of the processes used and patented for the 

 hydrogenation of oils. Oleic acid and hydrogen are made to combine and 

 yield stearic acid. "Thus 282 lbs. of oleic acid require 2 lbs. (or about 0.7 

 per cent) of hydrogen for the production of 284 lbs. of stearic acid, and simi- 

 larly the transformation of olein into stearin requires the use of about 0.6£ 

 per cent hydrogen. . . . 



" Since the addition of less than 1 per cent of hydrogen sufiices to convert 

 cotton-seed oil or other vegetable oils into a fatty body of the consistency ol 

 lard, it follows that manufacturers of ordinary lard compounds (that is to say. 

 a mixture of 80 to 85 per cent of refined cotton-seed oil and 15 to 20 per cent of 

 oleostearin) have promptly turned their attention to the production of the 

 compound by a ' self -thickened ' cotton-seed oil." 



See also a previous note by Bomer (E. S. R., 28, p. 616). 



Progress made in the field of tobacco chemistry, R. Kissling {Chem. Ztg.. 

 36 {1912), No. 135, pp. 1321-1323).— This deals with the progress made in the 

 cultivation and preparation of tobacco and the analysis of tobacco and tobacco 

 products during the last few years. 



