RECENT BOOKS PROUT'S HYPOTHESIS.ALEMBIC CLUB R ~ P R I N T NO. 20. Papers by William Prout, M.D. (1815-16). I. S. Stas (1860). and C. Marignac (1860). Edinburgh: Published by the Alembic Cluh. Edinburgh Agents: Oliver and Boyd, Tweeddale Court. London Agents: Gurney and Jackson, 33 Paternoster Row. 1932. 58 pp. 18.2 X 12.2 cm. $0.65. Prout's Hypothesisthat the atomic weights of the elements are multiples of that of hydrogeu--dates from the papers which Prout published anonymously in 1815 and 1816 in Thomson's A n m k of Philosophy. The first of these, entitled "On the Relation between the Specific Gravities of Bodies in th& Gaseous State and the Weights of their Atoms," contains more than a suggestion of Avogadro's Principle. The second paper is shorter and was written for the purpose of correcting an error in the first. Both are reprinted in the present Alembic Club Reprint, along with extracts from a paper of Stas (1860). which denies the views of Prout, and a paper of Marignac (1860) which aiticizes the paper of Stas and defends the hypothesis of Prout. The extracts from Stas end as follows"1 conclude then by saying: as long as we hold to experiment for determining the laws which regulate matter, we must consider Prout's law as a pure illusion, and regard the undecomposahle bodies of our globe as distinct entities having no simple relation by weight to one another. The incontestable analogy of properties observed amongst certain elements must be sought in other causes than those originating in the ratio of weight of their reacting masses." In spite of the experimental results of Stas. Marignac was convinced that the fundamental prin&iple of Prout's Hypothesis was valid. His paper contains a prophetic passage foreshadowing the idea of a ''packing effect" which Aston has recently stated as follows. "In the nuclei of normal atoms the packing of the electrons and protons is so close that the additive law of mass will not hold and the mass of the nucleus will be less than the sum of the masses of its constituent charges." Marignac argued in 186&"Could we not suppose that the cause (unhown but probably different from the physical and chemical agencies familiar to us) which has determined certain groupings of the atomq of rimo or dial matter so as to rive rise to OW -~ the sole -~~ chemical atoms, by imprersing on each of thew groups a special chnncter and particular properties, should not at the same time have exercised an intluence on the manner according to which these groups of primordial atoms would obey the law of universal attraction, in such wise that the weight of each group might not be exactly the sum of the weights of the primordial atoms composing it?" The present Alembic Club Reprint contains a feature which is an innovation in this series of reprints, an Historical Introduction, pp. 5-24, which greatly inaeases its interest and value. We think that the Introduction ought to carry the name of the scholar who wrote it, but we are grateful for it neverthelessas we are grateful to the Alembic Cluh for the publication of this latest addition to its series of the classics of chemistry. L. DAVIS TENNEY
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AN INTRODUCTION TO CHEWSTRY.Frank B. Kenrick, Professor of Chemistrv. Universitv of Toronto. The Universitv of 434 pp.. 33 Toronto ~ r e &Toronto, Canada, 1932. viii Figs. 14.5 X 22.75 cm. 8.00. The oumase of this book. as stated in the Preface. is "to interpret in loborolor) terms n numtm of the commoner wards such as constituent, dissolved constituent, compositmn, solution, pure substance, element, atomic weight, molecular weight, chemical formula, ion, dissociation, and same others." A great deal of emphasis is placed on the language of chemistry. The book is divided into nineteen chapters, entitled as follows: "the manufacture of salt, chlorine and caustic soda, meaning of the term constituent substance; composition; the refining of
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crude sugar, unsaturated solutions, supersaturated solutions. solubility, adsorption; the refining of crude sugar (continued). vapour pressure, boiling paint, partial pressure, and partial vapour pressure; mechanical mixtures, solutions, and pure substances; the elements; law of reacting weights, chemical symbols and formulas; water as a type of pure substances; the chemistry of water and of aqueous solutions; the constituent substances of water (oxygen and hydrogen), oxides and salts, valency; aqueous solutions; wood; the mass law, esterification, synthesis of ammonia, dissociation, electrolysis; air; rocks; methods of preparation--general; methods of manufacture, applications of rules of reactions, electrolytic processes; the periodic system of elements, Mendelejeff's table; chemical literature." The order and treatment are a radical departure from that in other textbooks. "A great deal of the traditional descriptive matter has been omitted, and the usual order of presenting it has been modified." We find in Chapter I that brine is pumped into an enormous tank called an evaporator, in which a "slurry" is obtained. Every 100 tons of slurry yield about 40 tons of salt and 60 tons of brine. The latter is subjected to electrolysis, chlorine, hydrogen, and "cell liquor" being obtained. The electrolysis of caustic soda is also discussed, as well as the manufacture of hydrochloric acid; also, the formation of water from hydrogen and oxygen. A great deal of stress is laid on quantitative relations, many equations being given, such as: 92.0 g. cell liquor ---3-
+ 8.78 g. caustic soda + 70.05 g. water.
13.17 g. salt
The author has much to say about a set of constituent substances On p. 18 one finds: "A set of constituent substances of a material is either a set of substances into which the material cm be turned quantitatively or a set from which it can be made quantitatively." His use of the term "constituent substances" does not correspond to general usage, nor to the derivation of the word constituent staluerel. Dr. Kenrick savs: "The term 'a con(Latin constituent substance' may be uscd for one or more substnnccs of a set of constiturnt substanccs." In Chapter 11.32 page. are devoted to compositiou. Raw materials, elementary composition, etc., receive attention. Composition of mechanical mixtures is also discussed. A page (43) is devoted to an alloy of copper and gold; and, long before symbols, nomenclature, etc.. are mentioned, the author speaks of "solid solutious of copper auride and copper." Indeed, symbols of elements are not given until page 170 is reached; brief mention of nomenclature is made on page 205, and valency is discussed on page 256. The author (p. 92) defines a mechanically mixed constituent as follows: "If the solubility of a conslituent of a material is the same as the solubility of the constituent substance, determined a t the same temperature and pressure and with the same solvent that constituent is a mechanically mixed constituent." Dr. Kenrick places pure substances and solutions under the head of non-nziztures (p. 96). He says that air, far example, is not a mchenical mixture of gases. He defines (p. 106) a solution as "an intermediafa member of a continuous series of mn-miztures." Reacting weights (p. 166) are used instead of atomic weights, and the term equivalent or combining weight is not mentioned in the index. The constituents of water (oxygen and hydrogen) are discussed in Chapter X (p. 224). Steel is not listed in the index. Chemical arithmetic is neglected. Enough has been presented to show that "An Introductiou to Chemistry" is unique both as to content and arrangement. While the author clearly shows that he is a scholar. he has given us a book which is somewhat fantastic. A better title would be "Selected Chapters in Chemistry."
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