Freeze-drying - Journal of Chemical Education (ACS Publications)

Freeze-drying. J. E. Cavelti. J. Chem. Educ. , 1950, 27 (5), p 288. DOI: 10.1021/ed027p288.2. Publication Date: May 1950. Cite this:J. Chem. Educ. 27,...
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SCIENTIFIC AUTOBIOGRAPHY AND OTHER PAPERS

Mox Plonck, Translated from German by Frank Gaynor. Philosophical Library, New York, 1949. 192 pp. 13.5 X 21 cm. $3.75. AWERhis death in 1947, several related articles and lectures written by Max Plsuck were collected and, prefaced by t,he memorial address delivered by Max van Laue, were translated to make this hook. Its nature is well indicated by the table of contents: A Scientific Autobiography, Phantom Problems in Science, The Meaning and Limits of Exact Science, The Concept of Causality in Physics, Religion and Natural Science. Besides being an absorbing firsbhitnd account of Planck's discovery of his famous constant, the first paper contains a number of arresting observations, such as: "A new scientific truth does not triumph by convincing its opponents and making them see the light, but rather because its opponents event,ually die, and a new generation grows up that is familiar withit." Iu the second article one of the "phantom problems" Planck discusses is the conflict between science and religion. Here he i s not clear her:mse he does not define what he means bv relieion.

wondrous in our picture of the universe, "...and he who has reached the stage where he no longer wonders about anything, merely demonstrates that he has lost the art of reflective reasoning." After such statements Planck's arbitrary dismissal in the last naner of the Christian's faith in the resurrection of Jesus comes aa by a follower of a.science which could not even explain the energy radiation of the sun until a few years ago is hardly justified. Up to the discovery of nuclear energy the existence of the sun was a. miracle! And no one can really explain such simple things as why we do not fall offthe earth or why a magnet attracts a piece of iron. Perhaps a more bumble and more scientific attitude would he: "We neither deny nor affirm until ts-e have tried the experiment Jesus asks us to try." W. F. LUDER NORTAE&STERN UNIVEBBITY Boe~on.M~ss~cnrrsmrs

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FREEZE-DRYING

E d W. Floadorf, F. J. st& Machine Co., Philadelphia. Reinhold Publishing Corp., New Yark, 1949. vii 280 pp. 6 3 figs. 19 tables. 16 X 23.5 cm. $5.

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no paid &nist&, no ritual, hit met in the homes of it,smembers for mutual instruction in the Kingdom of God. To Jesus a man's religion was his attempt to live as a citizen of God's Kingdom, an idea. that can remake the world, hut u-hieh the church has neglected for the very thing that Jesus condemned most emphatically. Planck, failing to inform himself sufficiently before writing on this subject, concludes that although the aims of science and religion aresimilar, their methods are i%ompatible. But Jesus, in advocating a praotical way of life, asked us to t r y the experiment to Iind out if it works-the scientific method. The method of Jesus and the scieutific method are actually the same. With atomic annihilation confronting us, the time has come to try the experiment of living as citiseus of the universe. Certainly history has shown us that the attempt to live as fragmented worshippers of the state, mammon, church, and science does not work. In the third and fourth essays the significance of the changes in physics for philosophy and religion i s challengingly interpreted. For example, on pages 92 and 93; Planck reminds us that every fundamentd discovery increases the olement~ofthe

FEW people seem to be aurare of the nature of the freeze-drying process, and of the fact that its industrial development occurred in the nick of time to make possible the wide distribution of serum, penicillin, and other biologicals which saved so many lives during the war. This book, by one of the leaders in that development, gives, in very complete and readable form, the history of the process, the fundamental principles on which it is based, its applications, bath those already in use and those which show possibilities for the future, and the v a ~ o u stypes of equipment available for its utilization, both on a laboratory and a plant scale. As the author points out, the idea of freeze-drying was inherent in Wallaston's cryo~horus.fimt exhibited in 1813. I t was not until the early years of the present century that any significant attempt was made to apply the process to the preservation of very labile biologicals. The early attempts were either abortive, or so time-consuming a s to render industrial development out of the question. The early workers were obsessed with the notion that the frozen mass must be kept in cold surroundings during the vacuum sutdim~itimof thr ier, ro~oplet~ly nrrl~otincthe wt4lknown fner 11131 t1.e heat of s u h l ~ r n ~uft i11.1. ~ ~ iw ~ n.wt he provided hy thr surrouti~lin~s.Sot uwll the 1!030'e war i t rrslvml

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that the frozen mass could he heated during sublimation, without melting, the heat provided being utilized so rapidly st the evaporating surface of the ice that the temperature of the frozen mass might still be retained at such a temperature as -20°C. This application of heat shortened the time required for the removal of the ice from days to hours, and was the necessary step in making the process practical. A rapid development followed and is continuing. Freeze-drying, the author shows, is applicable to various foodstuffs, although its expens-relatively minor in the preparation of high cost biologicals-becomes a seriously inhibiting factor. A thorough bibliography is appended to each chapter, a patent list is given, and, in an appendix, work done on the process a t M.I.T. durine the war is summarieed. and the use of freeze-drying . in the prepar&ion of anrutamieal spe&ens is described. The book can be recommended to all who are involved in research on biologicals, to all who are interested in a development which made possible the widespread use af serum, plasma, penicillin, and the like, and to those actually applying the process in industry. Chemists with imagination may also perceive possible applications to the isolation of unstable compounds or to the crystallization of those which tend to resist that procedure. J. E. CAYELTI Amr;onar*uC o r ~ k a a MEADVIGL.,PGNNBTLYANIA

PRINCIPLES OF ORGANIC CHEMISTRY James English, Jr., and Harold G. Cassidy, Assmiate Professors of Chemistry, Yale University, New Haven, Connecticut. International Chemical Series. McGraw-Hill Bwk Co., Inc., New York, 1949. xiii 512 pp. Illustrated. 16 X 24 cm. $5.

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T m s textbook for a year course in organic chemistry is written from a somewhat more theoretioal point of view than are most similar texts. The terms electropbilie and nucleophilic are introduced emly and used repeatedly. Possible mechanisms of reaetionsrarementionedfrequently. In fact, aslightly theoretical point of view is maintained throughout, even though the subject matter a s s whole is pretty much what we have come to expect. The hook opens with a short introductory chapter, largely of a. theoretical nature. I t is less extensive in scope than similar sections in tents that have long been well known. But whereas some of these sections have been little more than introductions to a traditional trest,ment of organic chemistry that from there on differed little from the presentation used for decades, this textbook uses constantly and even expends the limited theoret,ical material with which it opens. The following six chapters (106 pages) are devoted to the hydrocarbons, including aromatics. Chapters 8 to 19 cover simultaneously the aliphatic and aromatic members of the various common functional classes, starting with alcohols and phenols and ending with amino acids. C h p t e r 20, "Color and chemical constitution," is quite brief and draws the illustrative material largely from t,he field of quinones. Chapters 21 to 24, "Stereoisomerism," "Carbohydrates: the sugsrs," "Macromolecules: polysaccharides, proteins, and plastics," "Topics in biochemist,ry," are adequate but, except for the sugars, rather brief. The authors have wisely taken the stand that since this is a textbook and not a reference book, it should not contain more material then can reasonably be covered in a year course. Anyone, therefore, is likely to find some of his pet subjects missing. For the most part, however, the important basic material is certainly ~resented,the pruning having been done largely on the special topics type of material. As interesting as such material is, there is no real reason why an elementary organic chemistry textbook must contain extensive sections on natural and synthetic drugs, alkaloids, dyes, hormones, vitamins, terpenes, heterocyclic compounds, and sterols. There me many excellent references, pertinently and con-

cisely annotated. As usual, some will he useful mainly to the teacher, but many are suitable for student reading. The exercises are unusually numerous and seemingly very carefully compiled. The reviewer has long believed that most organic chemistry texts have been deficient in this respect. Students learn best by practice, and practice is more efficient when guided. Many of the exercises are of types commonly used in courses in qualitative organic analysis. I t is quest,ionable how much the average student in a first year course o m profit by some of these. The emphasis on this kind of exercise may be advantageous in courses with laboratory work consisting to a considerable extent of identifying organic compounds and separating mixtures of them. I t will he less helpful sud less meaningful in courses where the laboratory work consists larzelv - . of orwara. . tions. The authors deserve congratulations for having produced a book that is relativelv free of errors. A fair nro~ortionof tho* spoucd by r l w reviewer nwe in conuertim wirh systematic ~lllmcnclnturu,the lrcnrnicl~tof a.l&4l, irrv~&ntnlly.dren sccnrs insdequrre. Sinec the Inrgcsale iudusrri.*lu~ilir!rirmof such 2 process must be well known to the authors, it is interesting to speculate on what they might have had in mind when they wrote the statement on page 181, "Direct halogenntion. Not applicable in aliphatic series." Unfortunately, there seem to be no statements elsewhere in the book that would clearly correct the erroneousimpression that this issure to makeupon thestudent. This hook should be seriously considered by any teacher who wants a rigorous presentation of the fundzmentsls of organic ehemistrv from a somewhat theoretical point of view without too many frills, and who does not object to teaching aliphatic and aromatic compounds simultaneously.

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LAWRENCE H. AMUNDSEN U r r v e n a ~ rOF CONNECTICUT S ~ o n n sC o l r r s c ~ ~ c u r

ENCYCLOPEDIA OF CHEMICAL TECHNOLOGY. VOLUME IV: CINEOLE TO DEXTROSE Edited by Raymond E. Kirk and Donald F. Othmer, Professors and Heads, Deparhnents of Chemistry and Chemical Engineering, respectively, at the Polytechnic Institute of Braolrlyn. Assistant Editors, Jonet D. Scott and Anthony Standen. The Inter969 pp. science Encyclopedia, Inc., New Yark, 1949. xvi 19 X 27 cm. $20.

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THEindex letter "C" finally ended with a discussion of cyclohexanol and cyelohexanone; a total of 1947 pages devoted to this one index letter. As mentioned previously, because of the high quality of the articles no one will object to an increased coverage or increased number of volumes over the ten that were scheduled for the set. Some of the longer sections in Volume IV are: citric acid, clays, coal, coated fabrics, industrial coatings, cobalt and its compounds, coffee, colloids, color, colorimetry, columbium, conductometry, confectionery, conveying, coordination compounds, copper and its alloys and compounds, corrosion, cosmetics, cotton, cottonseed, orystaIlization, crystals, cyanamides, cyanides, cyanine dyes, oyclohexaue, dairy products (73 pages), datainterpretation and correlation, density, dental materials, detergency, and dextrose. The section on Data-Interpretation and Correlation by Prof. D. F. Othmer is particularly noteworthy. For the first time his method of making reference substance plots, which has been a p pearing as journal articles since 1940, is gathered into one article. The wide variety of topics covered in E. C. T. becomes more impressive as the volumes increase in number, so that their utility and need by students becomes greater. The library in the small college cannot afford to be without this set, for it will serve a large group of reference users. KENNETH A. KOBE Umvansmr on T s x ~ s

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