JOURNAL OF CHEMICAL EDUCATION
288 the same host while unrelated strains may produce an additive or even intensified effect. It follows that serological analyses of virus complexes, such as are considered in the next two chapters, offer a valuable complement to other techniques of biochemical assay. "The methods have been used to show not only that viruses which were thought previously to be unrelated, because they cause differentsymptoms or have different host ranges, are related strains. but thev h v e been valurtble also in demonatrah ing that some &nica71y similar diseasesa~etialogieall~ different!' From serological considerations the author passes on in the ensuing half of the book to the chemical and physical properties of purified vim8 preparations, crystallinity, particle and types of inactivation. As is well known, the electron microscope has given a greatly increased advantage to the physicochemical approach to the subject, since the particles concerned are under 200 mp in size. A concluding chapter on origins points out the relationship of the nucleoprotein extracts, currently known as or associated with viruses, to the many organic compounds, including enzyme systern, involved in cell metabohm. Unique in their property of self-multiplication, v i ~ s e smay represent, however, metabolites that under certain conditions develop in considerable excesP, Certainly, they can no longer be conceived as primordial, protoplasmic units. Here is a reference book that is invaluable to students and workers in both physical and biochemistry. ~
Errors have been few and the literature has been covered quite well for the type of audience for which this book was written. S. S. KIBTLER
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PROGRESS IN COAL SCIENCE Edited by D. H.Bangham,' Director of Research Laboratories, British Coal Utilisation Research Assodation. Interscience Pub. 456 pp. 32 figs. 27 ]ishers. New York. 1950. xi tables. 12 plates. 16 X 25 cm. $7. oonsiats of reviews a series articles which were privately circulated in the Monthly Bulletin of the British Coal Utilisation Research Asaooirttion during 1943-4,, The vie,,. was that Ma useful purpose would be served by making these available to a wider public. The selection of subjeeta for this volume , , , has heen dictated by the desire to present uptodate information in fields inadequately covered by existing textbooks. I t is hoped that this ohoice will be such as to appeal to a wide range ofreaders: to students. , .; to scientists in industry . .; and . . to workers in all countries engaged in the task of our knowledge of coal and of its technology and utili-
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The book covers five main fields of discussiou which in turn are subdivided into 26 chapters. In the first section entitled "Modern Experimental Techniques" are contained the following chapters: Cryetallographic Techniques in Chemical Analysis, Applications of Absorption Spectroscopy to Organic Compounds, Mass Spectrometry for 0 COLLOIDAL DISPERSIONS Chemical Analysis, Chromatographic Adsorption Analysis, Earl K. Fischer, National Bureau of Standards. John Wiley and Photographic Techniques in Combustion Research, and MeasureSons, Inc., New York, 1950. mi 387 pp. 71 figs. 67 tables. ment of Flame Emissivity. 15.5 X 24 cm. $7.50. The section on "Fine Particles" deals with Fine Powders and Particles in Industry, Particle Size Measurement, Assessment of ALTHOUGH the objective of this book iato covw dispersion%of Specific Surface by Adsorption Methods, Non-Mechanical solids in liquid media, it is almost entirely devoted to industrial Methods of Size Reduction, and Grindability of Coal. processes involved in producing surface coatings and inks. This Chapters on Formation of Humus and its Relation to Coal, limitation eliminates a vast amount of colloid chemical literature Analysis and Sempling of Solid Fuel, Occurrence of Rare Eleof less economic but considerable theoretical interest. It also ments in Coal Ashes, and Cod Petrology are found in the section limits the major attention to particles in the upper range of col- dealing with "Coal Constituents." loidal dimensions. The dimensional limits of colloidal particles Under the "Organic Chemistry of Cod Products" are chapters are defined in the hook as 1 micron and 1 millimicron, but with on: Action of Chemical Reagents on Bituminous Coal, Action the exception of carbon blacks, which range downward to 3 of Oxygen on Coal at Moderate Temperatures, Progress of Coal millimicrons, most of the attention is given to particles above Tar Research in the Period 1910 to 1940, Recent Work on Coal 50 millimicrons in diameter. Though this limitation of the book Tar, and Hydrocarbon Synthesis. is left for the reader to discover, it is a desirable one in order to The last section deals with "Chemical Aspects of Combustion retain the book within reasonable dimensions and to focus it upon and Gasification" and includes the following chapters: Combus; industrial andioations. in Fuel Beds, Some Kinetic Aspects of Gas Phase Combus; The hooc bopns with a verv . satisfaetorv discussion on oarticle tion tion, Sulfur Compounds in Combustion, Effectof Inorganic Comsim, it3 mcnning and rnmrurmwnt. Here is iouud a very read- pounds on the Behavior of Coals and Cokes, Coal Ash: Chemical able description of ihc mewing oi particle &e and the wght dif- Composition as a Guide to Behavior in Furances, and Recent ferent average diameters found in the literature. The measure- Developments in Gasification. ment of particle size by sieving, optical microscopy, ultramicrosThe purpose of the book in making more generally available to copy, electron microscopy, adsorption of gasea and vapors, sedi- coal invatigators the recent advances in speoialiaed fields has mentation, diffusion, X-ray measurements, and turbidity is given been fulfilled. However, because of the time lag involved, this adequate attention. In addition, detailed attention is given to purpose would be better served in the future if the original some of the more common pigments. BCURA articles themselves were given wider distribution. Following the discussion of particle size are three chapters The chapter dealing with non-mechanical methods of wise re devoted to the dispersed state and a discussion of such matters duction is, so far as the reviewer knows, the only published comas the solid liquid interface, the contact angle, adhesion tension, parison of the effectiveness of the various types of equipment despreading of liquids on solids, flocculrttion, and rheological prop- pendent on impact, attrition or explosion effectson the particles. erties. The last-named subject is dealt with in good detail, and I t is stated that "these novel methods of pulverizing are, in DlastiC flow, thixotro~v. ... and dilatancv have been clearlv. -Dre- general, less satisfactory thsn conventional mechanical methods. sented. For superhe grinding mechanical mills can hardly compete with The last third of the book is devoted to dispersing methods. the attrition type mill and the requirements of the gas turbine It gives a good outline of the influence of surface-active agents lend impetus to research on non-mechanical mills of all types." and of the current practice with roll mills, ball and pebble mills, In the discussion on "grindability of coals'' it is emphasized that disc and eone.mills, and dispersion by phase transfer. different t y ~ e of s minding tests olace coals in different orders of Altogether, the reviewer finds this book to be, within the limits 1 Deceased of its coverage, a very satisfactory presentation of the subject. GEORGE L. CHURCH
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