RECENT WORK IN AGRICULTURAL SCIENCE. 



AGRICULTURAL CHEMISTRY— AGROTECHNY. 



The production and treatment of vegetable oils, T. W. Chalmers (London: 

 Constable d Company Ltd., 1918, pp. XI +152, pis. 9, figs. 97).— This volume 

 deals with the production and treatment of vegetable oils, primarily from the 

 engineer's point of view. The material presented includes descriptions with 

 accompanying plates and diagrams of machinery for the various stages in the 

 production of oils, and chapters on the refining of oils, the hydrogenation of oils, 

 the generation of hydrogen, soap making, the recovery and refining of glycerin, 

 and the splitting of oils. 



In the chapter on extraction of oils by chemical solvents the relative merits 

 of the pressure and solvent extraction processes are discussed, with reference 

 particularly to the value of the I'esulting residue as a cattle feeding stuff and as 

 a fertilizer. The author is of the opinion that with modern methods the earlier 

 objections to the solvent process as yielding both cake and oils unfit for con- 

 sumption are unfounded, and that the residue from the solvent extraction 

 process can be used to better advantage than the press-cake as a fertilizer and, 

 with proper control of the amount of oil left in the residue, equally well as a 

 feeding stuff. 



Vegetable fats and oils, L. E. AndSs, trans, by C. Salter (London: Scott, 

 Greenwood & Son, 1911, 3. ed., rev. and enl., pp. XI+S51, figs. 93).— In the third 

 English edition of this book, the preceding edition of which has been previously 

 noted (E. S. R., 25, p. 801), the subject matter has been revised and enlarged 

 by H. B. Stocks to include modern methods for the extraction and purification 

 of vegetable fats and oils. 



Gums and resins, their occurrence, properties, and uses, E. J. Paeet (Lovr 

 don: Sir Isaac Pitman dc Sons, Ltd., 1918, pp. VI +106, pi. 1, figs. 6).— This is 

 a reference handbook on the occurrence, properties including analytical con- 

 stants, and uses of the more important true resins, gum resins, true gums, ])al- 

 sams, and medicinal resins. 



The natiiral organic coloring matters, A. G. Perkin and A. B. Everest 

 (London and Netv York: Longmans, Green <& Co., 1918, pp. XXII +655; rev. in 

 Analyst, U (1919), No. 516, pp. 119, 120).— This volume of the series of mono- 

 graphs on industrial chemistry edited by E. Thorpe deals with the properties 

 of the natural coloring matters, including a discussion of the facts which have 

 led to a determination of their constitutions. The history of the employment of 

 natural dyestuffs is traced in an introductory chapter. In the succeeding 

 chapters the natural dyestuffs are grouped according to the constitution, where 

 known, of their main tinctorial constituents. Where members of two widely 

 distinct groups are present in the same plant, the description of the plant is 

 given under the heading which from its present or past uses appears the more 

 suitable. 



An appendix contains lists from various sources of Indian natural dyestuffs, 

 natural dyes of the Philippines, British plants capable of dyeing mordanted 

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