I.VDUSTRIAL A N D ENGINEERISG CHEMISTRY
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that the dean has not allowed the making of a distinguished career in chemistry t o interfere in the least with the making of a very human individual. And it is this that brings us to what is perhaps the most delightful sidelight of his personality, and a t the same time explains one of the principal causes of his successful career. Throughout all the years that he has labored as a teacher and a scholar he has never allowed his broad sympathies to become dulled, nor has he become pessimistic regarding the continued progress of society. He has watched its changing ideals and has been confronted with the disquieting restlessness of modem youth, but his kindly sympathy and his innate conviction regarding the permanence of right principles and ideals have made him an optimist in his own home and out of it.
Vol. 23, No. 3
Doctor Coates has published a large number of valuable papers, but these publications represent but a fragment of his contributions in the form of collaborations with committees and individuals in various chemical fields. I n the Audubon Sugar School he formulated what was possibly the first course in chemical engineering offered in this country. He was probably the first to publish work on the “air activation of chars.” For many years Doctor Coates has been Councilor for the SOCIETY. He is Louisiana Section of the AMERICANCHEMICAL an honorary member of Alpha Chi Sigma, a fellow of the American Institute of Chemical Engineers and of the A. A. A. S., and a member of most of the chemical societies. u’.I,. OWEN
NOTES AND CORRESPONDENCE History and Development of the Modern Yeast Industry
Cs = 0.300
+ 0.00120t” C.
This formula is probably better than Mr. Schaphorst’s for extrapolation purposes, since it is known that the specific heat of the liquid rises rapidly as the critical temperature is approached. H. 0. FORREST E. W. BRUGMANN L. W. CCMMINGS
Editor of Industrial and Engineering Chemistry: I n his interesting paper under the above title ~ I x DENG. . CHEM.,22,1154 (1930)], C. N. Frey discusses the use of molasses as a source of carbohydrates, which, in his opinion, had not been successful until 1915, when Hayduck and also Wohl investiRESEARCH LABORATORY OF APPLIEDCHEMISTRY gated the production of yeast from molasses and ammonia. MASSACHUSETTS ‘INSTITUTE OF TECHNOLOGY I wish t o draw the attention to the fact that, more than twenty CAMBRIDGE, MASS. years before, H. Elion, of The Hague, succeeded in devising a January 24, 1931 process for producing a baker’s yeast of high quality from molasses. This process, Which was patented in several countries in 1895, is employed industrially on a large scale and was of especial use during the war [compare 2. angev. Chem., 39, 1584 Editor o j Industrial and Engineering Chemistry: (1926); J. Inst. Brewing, 36, 334 (1930)l. L. ELION The article under this title by M. J. Dorcas in the Novem’ber, 8 YPERSCAESTRAAT 1930, issue has a paragraph on the “Importance of Selecting SCHEVENINGEN, HOLLAND January 10, 1931 Proper Light Source,” which seems to give an incorrect impression of probable industrial conditions. Dorcas states that “most reactions have a uniform quantum efficiency,” and calculates that under this condition the energy requirement will be a minimum a t the lowest effective frequency (longest wave length). He concludes that “if cost of energy is an important Editor of Industrial and Engineering Chemistry: factor in the process, efficiency demands that the energy be I n reading the article by H. 0. Forrest, E. W. Brugmann, and ENG.CHEM.,23,37 (1931)], it seemed supplied with radiation of the longest wave length capable of L. W. T. Cummings [IND. causing the reaction.” to me that a good approximate formula on the specific heat of This statement is justified only when there is a constant quandiphenyl would be welcome. Consequently, I propose the tum efficiency and a constant absorption of radiation energy, following based on the curve of test results, Figure 5, shown on both independent of wave length, since the energy required by page 39: the reaction must be calculated on the basis of quanta absorbed, 0.001t 0.32 = specific heat while the cost is determined by the energy incident on the syswhere t = temperature of diphenyl in degrees Centigrade. tem. For example, the formation of vitamin D from ergosterol Of course this formula applies only to the temperature range has been shown by Marshall and Knudson [ J . Am. Chem. Soc., between SO” and 360” C., as shown on the curve. 52, 2303 (1930)] to have a constant efficiency of about 0.3 mol W. F. SCHAPHORSTpa- quantum absorbed over the range 3022 to 2300 A,; but 4 5 ACADEMY ST. because of variation in absorption, Fosbinder, Daniels, and NEWARK, N. J. January 9, 1931 Steenbock [ J . Am. Chem. Soc., 50, 923 (1928)l found that the incident energy necessary forothe same effect was eleven times as great a t 3020 as a t 2650 A. Editor of Industrial and Engineering Chemistry: Constant quantum efficiency, independent of wave length, The formula which Mr. Schaphorst proposed lies below the can hardly be said to be characteristic of most reactions. The data through practically the whole temperature range, and in following extracts from Kistiakowsky’s “Photochemical Procthe worst case, a t 260’ C., gives a value of the specific heat of ess” summarize the evidence: diphenyl which is 7.2 per cent too low. We suggest the following linear formula for the specific heat According to the Einstein-Stark equivalence law, the rate in the range 80’ to 300” C., which agrees with the data within of a photochemical reaction in light of different wave lengths the experimental error: must vary as the number of absorbed light energy quanta. Ex-
Ultra-VioletRadiation in Industry
A Formula for the Specific Heat of Diphenyl
+
