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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