Carl Wilhelm Scheele-Sein Leben und seine Werke (Zekert, Otto)

activation as computed from the Arrhenius equation with cer- tain modifications. To this end, the literature has been combed for reactions in solution...
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RECENT BOOKS THE KINETICSOF REACTIONS IN SOLUTION.E. A. ModwynHughes, D Sc. (Liverpool), D.Phi1. (Oxford). Lecturer of Trinity College, Oxford. The Oxford Press, New York City, 1933. vi 313 pp. 16 X 23 cm. $5.00.

Gesellschaft fiir Geschichte der Pharmazie. Buchdruckerei Arthur Nemayer, Mittenwald (Bayern). Part 1 (1931), 33 pp.; Part 2 (1932). 40 pp.; Parts 3-7 (1934). 303 pp. 65 illustrations. 19 X 25 cm. Part 1, paper, 3 marks; Part 2. paper, 2.20 marks; parts 3-7, paper, 12 marks, hound, 15 marks.

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This monograph can be most appropriately characterized as "Hinshelwood in Solution," for the author endeavors t o carry over to solutions the same approximate methods which Hinshelwood has advocated for the interpretation of gaseous reactions. In short, the attempt is made to interpret rates in solution by an equation of the form k = Z C E I R T where Z is the collision number as calculated from gas kinetic theory, and E is the energy of activation as computed from the Arrhenius equation with certain modifications. To this end, the literature has been combed for reactions in solution and an enormous amount of data organized in a way that will he of much service to investigators in the field. The author is to be commended for bringing t o light (p. 100) variations in rates with concentration which have not received adequate attention; also, for many stimulating suggestions of problems which need further investigation (pp. 101, 200, 201). Unfortunately, the treatment of the data is often more extensive than critical. For example, in Table 11, p. 79, if the corrections on p. 215 are applied to the ionic reactions 13,14, and 15, the good agreement claimed in the last column is reduced approximately hundred fold. Attention is directed to some of the marked discrepancies between theory and experiment which are passed over (pp. 216, 218). A noteworthy exception is the critical footnote on p. 124. That so simple a treatment cannot be generally applicable in solutions has been recognized for many years, and the author is obliged to suggest various subsidiary hypotheses (pp. 81-3) to save the theory. Previous to the appearance of this monograph, the author's thesis had been criticized by Polissar, D. T. Lewis, and Huddelston, and by the present reviewer in the I. Chem. Phys., 1,289 (May, 1933). None of these criticisms has been satisfactorily met (p. 168). The reviewer feels that i t is questionable whether the concept of a collision between a solute and a solvent molecule (pp. 18-21) can he assigned a sufficiently definite physical meaning so that the frequency of cbllision can be calculated without ambiguity. The argument (pp. 80, 168) assumes that it is legitimate to make long extrapolations to a common temperature using a simplified formula which has heen tested only within very limited temperature ranges. This may not be "the right way to regard the problem." On both experimental and theoretical grounds, i t is difficult to see why E should he a constant independent of temperature, although it may so behave over a limited temperature range. As the reviewer has painted out, the assumption of E as independent of T leads to themodynamic restrictions and contradictions when applied simultaneously t o reversible reactions. The treatment consequently must he rejected as a satisfactory solution of the problem. The are most frequently fact that values of Z between lo8 and encountered (p. 82) is hardly a cogent argument for the theory. It only proves that reactions having these values are easiest to measure and consequently more of them have been studied quantitatively. I t furnishes no evidence that such are the most common of all possible reactions. While the reviewer cannot accept the arguments as conclusive, the book nevertheless represents a valuable addition t o the subject. I t will be of much value to anyone who is interested in this broad field and is in a position to read it critically. VICTOR K. LAMER C O L ~ B l d UNIYBBSITY

NBW YOPKCITY

Although Scheele's fame rests upon his remarkable genius for discovering and isolating new elements and compounds, it must not be forgotten that he was a lifelong practitioner of pharmacy. Apprenticed to this profession, by his own choice, when not yet fifteen he remained true to this calling even after he had earned an international reputation as a chemist. Glittering offers from the court,from the scientific center of his native country, from foreign rulers, from industrial corporations, all were unhesitatingly rejected. He preferred to pursue the easy tenor of his life as the proprietor of an apothecary shop in a small town. From this modest station in life he derived a high degree of satisfaction from a task well done and when his vocation permitted he worked a t his beloved hobby, chemistry. The pharmacists are therefore justly proud of their colleague and this biography fittingly bears a distinctly pharmacic imprint. However, the work cantains much of interest t o the student of chemical history and many interesting facts appear here for the first time. The preface opens: "It has long been my desire to become acquainted with the places where Scheele lived and worked." This ambition was realized and the author patently made excellent use of his opportunities. I t is also obvious that he has made an extensive and competent study of the documentary material and the reader gains the impression that fint-band information is being imparted. The style is fluent, the touch sure, i n d the choice of material admirable. Items of nterest to the specialist primarily are segregated. The author assumes that his reader comes with the spade work completed and this monograph serves t o amplify and, in some instances, to correct the previous biographies. The emphasis is primarily an the life of his hero and comparatively little space is devoted to his achievements. Part 1 deals with Scheele's ancestors and his brothers and sisters. Part 2 discusses his childhood a t Stralsund and his apprenticeship a t Gothenburg. Part 3 is made up of the Table of Contents of the Compounding Manual written by Scheele's elder brother. This list which carries a commentary and glossary by Zekert is a logical part of this biography since it gives an insight into the numerous and varied preparations that Scheele himself learned to make in the pharmaceutical laboratory. The other Parts are devoted (one each) to Scheele's residence in Malma, Stockholm, Uppsala, Kaping. The illustrations which are excellently done are full of interest and they include a wide range. Typical are the baptismal record, the house in which he was horn, the apothecary shops (or their successors) where he worked, the window a t which he studied the effect of the solar spectrum on silver chloride, pages from his notebooks, his coffin plate, his tombstone, etc. By far the most important of the illustrations is that of an ivory medallion bearkg a painting of Scheele a t about his twentyfifth year. I t had been generally supposed that no likeness of Scheele was in existence and the various statues of him were fruits of the sculptors' imaginations. Quite by accident Zekert, in 1929, found in an obscure pamphlet a photograph made in 1886 of the medallion. At his instigation the search was begun and after many difficulties the original was finally discovered in Berlin. This treasure is now the property of the Apothecary Society of Sweden. The story of this important discovery is of course included in this monograph. The reviewer learned much from this excellent biography and he commends it t o all students of the history of chemistry. RALPH E. OESPER

CARLWILHELMSCHEEL-SEIN LEBEN UND SEINE WBRKE. Privat-Dozed Dr. Otto Zcknt, Wien. Herausgegehen von der

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