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Is Steam Decomposed b y Copper? Editor of Industrial and Engineering Chemistry: On page 1167 of the December issue, in the valuable article on the “Effect of Atmospheres on the Heat Treatment of Metals,” by Coriolis and Cowan, is the statement that “the earliest lessons in chemistry have taught him [the chemist] that steam passed over heated copper is broken down with formation of copper oxide.” I have always understood that steam is not decomposed by copper. Jago, in his textbook of inorganic chemistry, states: “At a red heat copper combines readily with oxygen but is unable to decompose water a t any temperature.” Roscoe, in his textbook, states that “steam is not decomposed by metallic copper a t red heat.” In view of these statements it would be interesting to know which is correct. T. H. BYRON WIGANCOAL& IRONCo., LTD. WIGAN,ENGLAND December 24, 1929
............ Editor of Industrial and Engineering Chemistry: There seems to be some difference of opinion with regard to this matter as indicated by the usual college texts. For instance, Alexander Smith’s “College Chemistry’’ says on page 411 :
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“It [copper] does not decompose water a t any temperature.” Remsen’s “College Chemistry,’’ page 546, says: “it [copper] decomposes water only a t a bright red heat.” I n Mellor’s “Comprehensive Treatise on Theoretical and Inorganic Chemistry,” Vol. 111, page 73, in the article entitled “Copper,” I find the following notes : In 1800 J. I,. Proust reported that water is decomposed by copper. H. V. Regnault found that the water is slowly decomposed a t a white heat forming cupric oxide. S. Kern noted the formation of oxides of copper when steam is superheated in copper tubes; and G. K. Elliott found that under these conditions the copper becomes crystalline and brittle. I,. Wohler and 0. Bale studied the equilibrium of steam in contact with copper a t 450” C. and observed no other than cuprous and cupric oxides are formed. According to M. C. Schuyten, copper reduced by hydrogen does not decompose water even if potassium permanganate were present, nor could W. Van Rijn or M. M. P. Muir detect any action of distilled water in copper.
It would seem from these additional references that there is some difference of opinion with regard to this matter and we wish to thank you for calling our attention to it. I n preparing our paper, we had not consulted any of the authorities, but had in mind only recollections of earlier studies. R. J. COWAN S U R P A C ~C ~ W J ~ T I O COMPANY N TOLEDO,OHIO March 6, 1930
BOOK REVIEWS Colloid Symposium Annual (E’ormerly Colloid Symposium 19. The Chemistry of Bacteria and the Development of a Practical Technique for the Chemical Analysis of Cells. Treat B. Johnson. Monograph). Volume VII. Edited by H. B. WEISER. 20. Human Blood Serum as a Colloidal System. S. Dew. Ludlum, 296 pages. John Wiley and Sons, Inc., New York, viii A. E. Taft, and R . L. Nugent. 1930. Price, $4.50. 21. The Lieserang Phenomenon in Gall Stones. J. E. Sweet. -~ 22. Studies on the Porous Disc Method of Measuring Osmotic Pressure. This volume contains the papers presented a t the Seventh J. C. W. Frazer. Symposium On at the Johns 23. Adsorption and the Permeability of Membranes. Harry B . Weiser. Hopkins University in June, 1929. Titles and authors of the This volume is an excellent indication of the growing interest twenty-three papers are as follows: in colloid chemistry and of the manifold applications of the 1. The Scattering of Light in Sols and Gels. F. G. Donnan and K . science. I t is gratifying to see many new names among those Krishnamurti. contributing to the success of this important annual symposium. 2. The Structure of Gelatin Sols and Gels. S. E. Sheppard and J. G. It is also gratifying to see colloid chemistry rapidly emerging McNally. from the inexactness of a qualitative science to one which is 3. The Measurement of Hydration of Gelatin and Similar Materials and founded on exact quantitative measurements. the Relation of Hydration to Swelling. Harvey -4.Neville and As has been pointed out by others, qualitative experiments, Edwin R. Theis. while often interesting, a t the same time are likely to produce 4. The Influence of Adsorption on the Growth of Crystal Surfaces. more confusion than clarity, and this surely was the case in Karl F. Herzfeld. the early days of colloid chemistry. The present volume con6. Crystal Structure and Adsorption from Solution. Wesley G. France. tains many quantitative data with adequate descriptions of 6 . Significance of the Electrocapillary Curve. A. Frumkin. experimental technic, and these, with the conclusions drawn, 7. Determination of the Number of Free Electric Charges on Air Bubbles constitute a record of accomplishment which will be of permanent and Oil Droplets Dispersed in Water Containing a Small Amount value.-J. H. MATHEWS
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of Cetyl Sulfonic Acid. James W, McBain and Robert C. Williams. The Electrostatics of Flotation. H. B. Bull. Some Evidence on the Nature of Extra-Molecular Forces. Donald H . Andrews. The Adsorption d Vapors. Walter A. Patrick. The Specific Surface Area of Activated Carbon and Silica. F. E. Bartell and Ying Fu. Compound Formation with a Volatile Base or Acid. Wilder D. Bancroft, C. E. Barnett, and B. C. Belden. Nature of Interaction between Hydrous Oxides and Mordant Dyes. Otto Reinmuth and Neil E. Gordon. The Apparent Specific Gravity and Moisture Content of Clay. Frank K. Cameron and Richard A. Lineberry. Progress in the Study of Clay Minerals. Edgar T . Wherry, Clarence S . Ross, and Paul F. Kerr. The Colloidal Nature of Some Finely Divided Natural Phosphates. K. D. Jacob, W. L. Hill, and R. S. Holmes. The Nature of Flow. Eugene C . Bingham and Baxter Lowe. The Adsorption of Fats from Volatile Solvents. Harry N. Holmes and Clifford J. B. Thor.
AND Milk and Milk Products. BY C. H. ECKLES,W. B. COMBS, H. MACY. 365 pages. McGraw-Hill Book Co., I n c , Xew York, 1930. Price, $3.50.
Present-day dairy practices involve chemistry and bacteriology to so great an extent that prescribing a one-year course of study for students not familiar with both of these sciences seems a hopeless task. The assumption that the students have some knowledge of chemistry has, however, greatly aided the authors in the presentation of t h e chemical, physical, and nutritive properties of milk-Chapters I1 to V, inclusive. Chapter VI, on microorganisms, is written to familiarize the student with certain morphological and growth characteristics of the type of organisms encountered in dairy practices. The material presented in these chapters is well chosen, though too abbreviated in many instances. The subjects treated can be supplemented by the instructor, but for the student who desires to go beyond a mere statement of fact the
