RECENT BOOKS but we do not like t o have a curious pupil ask why mercury and not give him the is written 2Hg in the equation and oxygen 01 real explanation. The carbon orcle is eiven a half-oaee . - of exolanation and the nitroeen or& does -*... -.-not aooear a t all. These relationshios are all-important in life and deserve full explanation even k the first year of chemistry, while the arc process of fixation of nitrogen, the chamber process of making sulfuric acid,and the LeBlanc soda process may well be omitted, for they are practically obsolete. The usual queer statement of the preparation of chlorine appears as i t has in the past even by college authors. "Manganese tetrachloride is unstable and as rapidly as i t is formed breaks down into manganese chloride and free chlorine." Must we think it formed, only t o be unformed without change of condi-
HIGH SCHOOLCHBMSTBY. George Howard Bruce, Department of Chemistry. Horace Mann School far Boys, Teachen' College, Columbia University. World Book Co., Yonkers-on-Hudson, New York, 1933. Revised edition. x f 550 pp. 147 illustrations. 12.5 X 18.5 cm. $1.68.
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A typical textbook in chemistry of the conservative, traditional ass is presented as above described. Good features are plentiul, among them being a clear concise style of diction which 6Us the book with a wealth of information for its size, a very thorough treatment of the electronic structure of atoms with a .onsistent application of i t to the major facts of chemistry. The clear, readable type makes the pages attractive. The line drawings are d e a r even in perspectives. Some half-tones are very muddy and some portraits of scientists may well have been omitted for lack of iustice t o these men of note. Heavy-faced type is liberally used. which is preferable to the use of much lower
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~h;&or modestly admits the book t o be "the outcome of a desire t o prepare a sdentifically up-to-date text which highschool students can read and understand, a text in which the language employed is that which they themselves use and comprehend." Warned by this statement we were prepared t o 6nd even some slang ohrases in the book but the best found was this caution: "seethat no W e comes near your hvdroeen zenerator." Flamine vouth must be restrained where fall the shadows of Horace n k n o . Ilowcrer, we must remind the author that prohibition days are over for a time and it were better pedagogy to train the boys under what conditions flnme may be introduced to the hydrogen generator with perfect safety. The usual text of this type is quite didactic. But the first psge starts with an inductively interesting lie situation t o explain a chemical change by the change of characteristic pmperties. When the discussion runs into the definition of a chemical change a- a change in composition, then the unknown is being explained in terms hardly known to the pupil. This is the usual error in invoducin~ terminology ahead of experience. The presentation of the law of t h t conservation of mass is perfect in its e5ectiveness of induction, even to the simple accompanying experiment t o draw out the pupil's interest in trying to test it himself. If this manner of presentation were used as consistently as the interweaving of the electronic theory with the facts of chemistry little more could be done to improve the eflectivenes of the book as a text. Science terminology increases like taxes and either causes revolt or pupil "boners." Aqueous tension,molar solzrlwn, and many others may well he omitted in first-year chemistry or be more simply stated. A recent result of the plethora of scientific terms was found in the pupil's reference to "a noted aeronaut who went up in a balloon t o study cosmetic rays." We can be so uo-tc-date with the subiect matter of science that we beein to overload the pupil and the public with the subject matter. The rcviewpr would ask text writers why we cannot be more upto-date in the manner of presentotiun. Why are thc preparations and properties of many elements and compounds so religiously given in the textbook, when we have the pupil go over all this gmund in the laboratory t o discover what has already been stated in the teat? Further, why should we take pains to distineuish obvsical and chemical orooerties? Is i t because we . . . . are sochemieally-pure minded that we cannot think of a property. much less l a m it, unless it is labeled as one or the other? Karure mixes them up with every substance and that is the way we find them in life, so why not be content t o study the chemistry of life rather than the chemistry of the textbook? Completed chemical equations are introduced in the first chapter and consistently given even though the usual explanation is not given until page 114. Probably much that we think we teach is passed over without understanding by the pupil so the matter of equations may be added to the lot without much fault,
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ALEMBICCLUB RBPRINTNO. 21. ON A NEWCHEMW TIIBORY m R E S B ~ E H BON S SALIC~IC ACID. Papers by Archibald Scott Couper (1858). Edinburgh. Published by the Alembic Club, Edinburgh Agents, Oliver and Boyd, Tweeddale C a d ; London Agents, Gurney and Jackson, 33 Paternoster Row. .,,DO
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At Townhead, Kirkintilloch, Scotland, on March 31, 1931, a tablet was unveiled with the inseription, "This placque marks the birthplace of Archibald Scott Couper, born 1831, died 1892. whose brilliant pioneering contributions t o chemical theory have won for him international renown, and whose genius, s t a e d by an early illness,was denied the opportunity of consummation.'' Couper received his early training in the Universities of Glasgow and Edinburgh; then Germany attracted him and he began the study of natural science and chemistry in Berlin. A youth of twenty-five, he migrated to the laboratory of Wurtz in Paris. Here he devoted his energies to practical work in organic chemistry and soon showed himself a capable investigator. T o him we owe the preparation of the mono- and di-bromobenzenes. and a study of the action of phosphorus pentachloride on methyl salicylate. The results of this latter research were disregarded for years, until A n d i i t z repeated it and showed that i t was experimentally correct. T h e papers in the Alembic Club Reprint are taken from the Cmn$fes rendw, 46, 1157-60 (1858); the Phil. Mag.. (41, 16, 104-16 (1858); and the Edinburgh Neu Philoso~hicaJ Journd, New Series,8,213-7 (1858). T h e keen young Scotchman begins his article "On a New Chemical Theory" as follows: "The end of chemistry is its theory. The guide in chemical research is a theory. I t is therefore of the aeetest imoortance t o ascertain whether the theories adopted by chemists arc ndequate to rhe explanation of chemiwl phenomena or are a t Icmt based upon thr. true principles which ought to regulate scientiric rcscarch." Thrn he goes on tostate: "There are two conditions which every sound theory must fulfill: 1. I t must he proved to be empirically true. 2. It must no less be philosophically true.'' These auotations show Couoer's attitude of mind. which led t o the followine hasic conclusions. usinr olesent-dav terms: ~~~~. Carbon is di- or quadri.valcnt in irs combination with hydrogen. ouygcn. sulfur, etc. Carbon can combine with itself, giving risc to the great number of carbon compounds. He writes graphic formulas in which the mutual bonds of the atoms are indicated by dotted or connecting lines; these are true structural representations of the type used today. Anschiitz also points out that, by slight changes in hi formula for salicyclic acid. Conper might have anticipated the benzene ring of Kekul6. As it is, Couper was an independent dis~~~~
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coverer of Kekule's postulates. Had it not been for the delay of Wurtz in presenting this paper to the French Academy, Couper's priority would have been recognized, or a t least his name would have been linked with that of Kekule as a co-discoverer of the fundamental theories that brought order into the chemistry of carbon. This lack of recognition, coupled with a later illness, led to his withdrawal from active chemical life, and the world lost a master who might have made far-reaching contributions to chemical fact and theory. I t is but an act of justice that his work should be represented in this series of chemical classics. [For a complete account, see "Life and Chemical Work of Archibald Scott Couper." by Richard Anschiitz, Proc. Roy. Soc., Edinburgh, 19, 193-273 (1909).] Taa UwrvB~srrvon K m s * s F. B. DAINS LAWRBNEB. KANSAS MATERIE (STRUCTURE O P MATTER). Four lectures by P. Debye, Director of the Institute of Physics. University of Leipzig. S. Hirzel. Leipzig, 1933. 50 pp. 21 Figs. 15 X 22 cm. Paper hound: RM 3. In German.
~ U K T V RDER
For some fifteen years P. Dehye has conducted a series of researches bearing d i i t l y on the atomic and molecular structure of matter. Four major fields have been investigated and in each he has obtained results of the mast fundamental importance. The fields are: X-ray determination of the arrangement of atoms in single molecules, X-ray investigation of the arrangement of molecules in liquids, the relation of dipole moments to chemical structure in liquids, and the behavior of strong electrolytes. In each of the fields be has correlated the results of physical measurements with the chenlical behavior of matter. During 1932 Prof. Dehye gave a series of lectures on his researches at Massachusetts Institute of Technoloev. Ohio State . University. nnd the University of California. After the lecture tow he wrote the four lectures of this booklet in response to a demand for a non-technical review of the work in the four fields mentioned above. The lectures are written in popular style and none of the (sometimes difficult) mathematical reasoning is included. He stresses applications to chemical behavior in each. Lecture one is an account of the author's work on X-ray interference from single molecules. When a beam of X-rays is passed through a gas the molecules scatter independently because of their random arrangement. However, peaks in intensity are found in the radiations from some gases. Debye showed these to he due to interference in the rays scattered by separate atoms within the molecule and established a method for the determination of interatomic distances from the X-ray pattern. Measurements have been made on many of the simpler molecules and the space structure determined. The results confirm the structures long postulated by sterewhemistry for methane derivatives, for cisham isomers, and for the benzene ring. The second lecture is on dipole moments and their relation to structure. Permanent and induced moments are simply explained and experimental methods are cited whereby the two may be separately detected. A bit more experimental detail might he appreciated by the lay reader hut this information is readily obtainable in American journals. A few specific applications of dipole moment data to chemical structure are given. In lecture three Prof. Dehye delves a little deeper into the structure of liquids. After pointing out that the Van der Wads' equation cannot describe the condition of molecules in a liquid, he cites two experiments as proof that the molecules in a liquid are very regularly arranged and even approximate the condition of a solid. When supersonic waves are passed through a liquid the vibrations of the molecules set up such standing waves that the liquid acts as a reflection grating and spreads white light into a spectrum. This is related to a tightly bound condition of the molecules. When a beam of X-rays is allowed to strike a mercury surface the reflected rays show interference peaks. These may he used to calculate a probability curve for the arrangement of the atoms. Certain positions, roughly corresponding to a packing of hard spheres, are found most probable ~
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from the calculation. Thus he shows that the liquid has a qnasicrystalline structure. Lecture four is a review of the fundamental developments in the now famous Dehye-Hiickel theory of strong electrolytes. The booklet is too brief for a thorough review of any subject but does provide a good survey of recent accomplishment. W. C. PIERI~NIYBPSITI OF CAICAGO CBmAM. ILLINOIS
OUTLINES OE ORGANIC CAEHISTRY.F. I.Moore, Late Professor of Organic Chemistry. M. I. T. Revised by W. T.Hall. John Wiley and Sons. Inc.. New York City. Fourth edition, 1933. xii 338 pp. 15 Figs. 14 X 24 cm. $2.75. This text, appearing now in its fourth edition, was first published in 1910, and was written expressly for those "who study Organic Chemistry from the non-professional point of view." Since the book was based on a course of lectures delivered to candidates for the bachelor's degree in Physics, Biology, and Sanitary Engineering, certain subjects, assumed to be of interest only to the professional organic chemist, have been omitted entirely or dismissed with a few words. Although there is sure to he dsereuce of opinion in regard to choice of topies, many will he surprised to find the principal discussion of the Grignard reaction relegated to about half a page of fine print. The amission of a discussion of acetoacetic ester is perhaps justifiable, but the fact that some organic substances are capable of existence in diierent forms possessing different properties would seem to he of interest to the non-professional student, and to illustrate admirably an important general phenomenon. C i s trans isomerism is likewise not treated in the text, but the student is asked to develop the basic ideas for himself in a study question. The text contains two statements to which the reviewer must take exception. Certainly the production of n-butyl alcohol from corn is an important process, and the alcohol a substance of considerable practical value, yet we read, "The butyl alcohols are of little practical importance, although the normal primary compound can now be obtained cheaply from glucose by a fermentation process and is often used as a solvent." Similarly we do not believe that the inference in the statement, "Attempts to prepare alcohol from acetylene and ethylene have resulted in the taking out of various patents, but while sugar is cheap and the market near, molasses will remain the chief source of industrial alcohol," is justifiable, far the production of ethyl alcohol from ethylene is today an industrial reality. There are a few minor errors or omissions, the elimination of which would improve the work. An excellent discussion of esterification is marred by the entire absence of any mention of the importance of catalysis with respect to the reactions involved. Dehydrogenation as a substitute for oxidation in the preparation of aldehydes and ketones is not mentioned, and the reaction involved in the Fehling's solution test is written as though it involved the copper-tartrate complex instead of the copper ion. The term "split" used in connection with the separation of optical isomers seems to us unfortunate, for it conveys a distinctly erroneous impression, and yet it is the only term which is used to express the basic idea involved in the resolution of racemic substances. The formula written far ascorbic acid on page 234 is not the one which has gained widest acceptance. T h e mechanism postulated for the reactions involved in the bromination of benzene is, we believe, incorrect. Few, also, will agree that the "most important method for the preparation of phenols consists in boiling the diazouium salts with water." The discussion of the polymerization of dienes to ruhber-like substances includes no mention of the similar behavior of chlorcprene, a reaction certainly of more importance than any involving dimethylbutadiene and butadiene which are mentioned. Since the text is to be used hv those whose maior interests lie outside of chemisrry, the inclusion of a few line drawings showing schcrnarically how reactions discussed are actually applied indusrrially or carried out in the laboratory would aid materially in stimulating the interest of the reader. The text is well written, readable, and almost entirely free from typographical errors, of which the reviewer was able to find
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