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variety of foods and other materials by several committee members.” As a result of such collaborative effort the methods given can be used with confidence. In addition, various sections of the book have been reviewed by men in whose laboratories analytical work on the various vitamins is in progress. The first chapter deals with sampling for vitamin analyses. One chapter each is devoted to the following: calorimetric and ultraviolet absorption methods for vitamin A; chromatographic and solvent partition methods for physiologically active carotinoids; thiochrome and fermentation methods for thiamine; fluorometric and microbiological methods for riboflavin; microbiological method for niacin; visual titration method and colorimetric methods with 2,6-dichlorophenolindophenoland 2,4-dinitrophenylhydrazine, respectively, for ascorbic acid. For each of the various methods one procedure is outlined in great detail, including sample calculations. Comments on individual steps are extensively interspersed between the directions for the various manipulations of the procedures. At the end of each rhapter there is a brief section on the applications of the given methods t o various biological materials, followed b y a selected bibliography. .Methods of bioassay for vitamins have apparently been purposely omitted from this volume. Methods for vitamins D, E , K, for biotin, folic acid, p-aminobenzoic acid, inositol, choline pantothenic acid, and pyridosine are referred to only through a selected bibliography. The methods presented in this volume are given in such detail that personnel with relatively limited analytical training should be able to apply them for routine work. Few crrors or misprints have been noted: on p. 100 the statement that “riboflavin is reversibly reduced to a leuco base, a dehydro compound,” should be corrected to read “a dihydro compound”; on p. 118 reference (48) is given to an important paper by Strong but this reference is not included in the bibliography. In view of the extensive use of photometric and spectrophotometric measurements in the methods published, a brief discussion of photometry and spectrophotometry would be a desirable addition to this book. Also, in the section on the chromatography of carotinoids it would be well to state clearly the relative position on the adsorption column of the various carotinoids. Methods of Vitamin Assay is well organized and clearly written. I t should be available in every laboratory wliere work on vitamins is in progress. I t is t o be hoped that future editions of this book will include methods on other vitamins.
M. 0. SCHULTZE. .Iftinographs on the Progress of Research in Holland. The WeL Purijkation of Coal Gas and Siniilar Gases b y the Staatsmijnen Otto Process. By H . A . PIETERS AND D. W. VAN KREVE55 pp. Amsterdam and Xew York: The Elsevier Publishing Company, Inc., 1947. This volume is No. 15 in a series of Monographs on the Progress of Research in Holland During World War 11. This book deals with past and current methods of removing hydrogen sulfide from manufactured gases and presents developments of the Otto process, which usrs an ammonium hydroside solution as a scrubbing medium plus a newly employed method of regeneration of elemental sulfur from the hydrogen sulfide so removed from the gas. In eight chapters it presents, successively, a review of liquid puriiirat ion procrsses. with comparative flow diagrams; a description of the Staatsmijnpn-Otto process; the constitutiorrand properties of the iron cyanide complex which is employed HS the catalyst o r oxygen (marrier in the second stage of the S.hf.0.process, for the wnversion of the HS--ion to sulfur and H+ ions; the general principles of gas absorption largely BY outlined in T. Ii.Sherwood’s Absorption and Ertraction (1937); experimental data and discussion of the velocity of ahsorption of hydrogen sulfide in the S.M.O. process; a discussion of the velocity of oxidation of the absorbed hydrogen sulfide, in terms of the HS- concentration, the concentration of the catalyst, the osygen pressure, and the concentration of dissolved salts [(SHai:S04, SH,Cl] in the absorpticn medium, with a comparison of laboratory arid industrial plant values for capacity factors; a discussion of by-reactions leading to polysulfide, thiocyanate LEN.
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and t o thiosulfate in terms of the operating variables; and a sumniary of results and oonclusions together with a tabulation of results obtained on oven gas a t an industrial installation at Tetre, Belgium. A bibliography of literature on the liquid purification of g” follows Chapter 1. The description of the S.hl.0. process as applied is good. The composition of the oxidation catalyst-“Prussian blue”-is complete, with lattice diagrams illustrating Prussian blue and Prussian white; a coagulated suspension of the two serves aa the actual catalyst. The theoretical discussion of the principles of absorption is adequate, although the authors’ contributions t o the whole theory might have been more clearly indicated. They state, ‘‘. our own experiments have enabled us to derive dimensionless relations with the aid of which the values of the transfer coefficients can be calculated (Tables 5 and 6)” and on the rate of absorption of the hydrogen sulfide they summarize as follows: “the absorption effect rises with (a) increasing ammonia and decreasing salt concentration of the solution; (bj increasing irrigation (liquor flowj and decreasing gas velocity; (c) increasing height of the washer. The temperature has only a slight effect.” They state that “for every experiment the values of kl and ko,in the general relations
..
S = K,.I(P,
- Pl)m
were derived and summarized in Table 7, p. 32, As a mean value we found:
For technical washcrs the ranstants C1 and k,, arc inostly smaller (2 to 5 times) than for laboratory scrubbers, as a result of insufficient wetting and channelling effects of the liquid in big scrubbers.” Relative to reartion rate (“oxidation velocity”) of the oxidation of the hydrogen sulfide, the authors summarize in thesc words: “The time of oridation is directly proportional to the initial concentration of HS’ ions and inversely proportional to the partial oxygen pressure; i t increases with the snlt content of the solution (decreasing H ) , with the temperature (decreasing H ) , when the diameter (d) of the bubbles increases, and when the quantity of air ( u j which passes through the aerator diminishes; i t is not dependent on the concentration of the suspended ‘white’, and ‘the tinie of oxidation as a function of the temperature is characterized by a minimum a t 30°C. This ran be esplained as follows: Below 10°C. the HS’ is oxidized to S. Between 10 arid 30°C. H. secondary reaction occurs (the formation of polysulphide and its oxidation to thiosulphate) which draws part of the 11.3‘ from the main reaction with the result that the time of osidation diminishes. At 30°C. the influence of the secondary reaction has reached a msxinium. A b o v ~that temperature the time of oxidation increases with the temperature in agreement n i t h our theory. “The products of the parasitic serondary reactions (formation of thioaulphate and sulphocyanate) are derived from polysulphide which in its turn is the reaction product of
* The value of the dimensionless constant CI was derived from separate experiments on the absorption of ammonia in dilute sulfuric acid.
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ammonium sulphide and sulphur. In those parts of the S.hf.0. installation wherc the liquid is in the reduced state (i.e., in the washer, the tanks and part of the aerator) so t h a t the HS’ ions can react with finely divided sulphur, polysulphide is formed” and “polysulphide solutions greedily absorb oxygen. The oxidation product is thiosulphate. This means the degradation of a corresponding quantity of sulphur which we want to minimize.” “The oxidation is not only limited to the polysulphide but (especially a t low PAvalues) the HS’ is involved as well. Experiments proved that in the absence of polysulphide, HS’ is involved as well. Experiments proved t h a t in the absence of polysulphide, HS’ is much less sensitive t o oxygen. This is obviously a case of induced oxidation.” The reactions of the cyanide ion with polysulfide, thiosulfate, and nascent sulfur are discussed, but the authors project the separate removal of hydrogen cyanide. The summary provides quantitative values for the power factors, services, and efficiency of hydrogen sulfide removal suitable for cost estimations. Metric units are used throughout the book. R. L. BROWN.
+
Microcalorimetry. By W. SWIETOSLAWSKI. x 190 p p , ; 56 fig. Yew York: Reinhold Publishing Corporation, 1947. Microcalorimetry is the measurement of small amounts of heat in which the temperature change or the rate of temperature change of the calorimeter is very small. While this book reviews the whole field of microcalorimetry, the work of the Institute of Technology in Warsaw, Poland, where the author was Professor of Physical Chemistry before World War 11. is described in greater detail. Professor Swietoslawski is not as well known in this country for his work in microcalorimetry as for his work in ebulliometry and the comparative iiiethod of measurement by which properties are determined by comparison with standard substances. Because of the considerable work in the field of microcalorimetry b y Professor Swietoslawski and his colleagues, this volume will be especially interesting and valuable to those concerned with calorimetry. This book covers methods of microcalorimetry rather than results. Types of microcalorimeters are discussed, among them twin calorimeters, the Bunsen ice calorimeter, the adiabatic calorimeter, and a labyrinth flow calorimeter. Accessories, such as thermostats, calorimeter jackets, and thermometers, and methods of correction for heat losses are included. Applications to some important problems are discussed also. The application discussed most extensively is to the measurement of the energy of radioactive radiations, including a-,8 - , and 7-rays. There is a bibliography of about 200 references a t the end of the book. F. G. BRICKWEDDE.
