Proceedings a paper on chemical equilibrium in dilute gaseous mixtures and in dilute solutions. Those two first papers supplemented each other and laid the ground-work. But it was only after the appearance of the papers which are printed in this volume that the theories of electrolytic dissociation and osmotic pressure began t o bear h i t . They still continue to hearabundantly. This slender book is easy and interesting reading. I t shows the origins of some of the most significant of physico-chemical theories and shows them in s manner which makes i t easy t o undwstand that the theories man found general acceptance and wide application in experimentation perhaps and research. It is curious-r it is not so curious-that these original documents seem more sincere, more apprehensible, more convincing than the expositions of the same theories which are printed in the textbooks. Textbooks are commonly dogmatic, hut the man who UNIVBRSWY OI MARYLAND CDLLBDB P A R % MD. has discovered the generalization necessarily puts it forward in a persuasive The lfoundations of the Theory of Dilute manner with an eye to the arraying of Solutions. Papers on Osmotic Pressure the evidence. by J. H. VAN'T H o m and on Electrolytic +The Alembic Club Reprints ought to be Dissaciation by SVANTBARRHBNIUS. accessible t o all students of chemistry. 1887. Alembic Club Reprint, No. 19. Many students will find that they can get Edinburgh: Published by the Alembic from the masters a quicker and a clearer Club. Edinburgh agents: Oliver and understanding of the puzzling things in London their science than they can from the textBoyd, Tweeddale Court. agents: Gurney and Jackson, 33 Pater- books. And, having seen the story in its noster Row, 1929. 67 pages. 12.3 X growth, they will have the story for good. 18.3 cm. Price, $0.65, post free. An understanding of origins is a useful aid toward the understanding of the present This latest number of the Alembic Club status of a science. But it is important Reprints contains an English translation for another reason. The present status of two papers, one by van't Hoff on "The changes. The origins do not. R61e of Osmotic Pressure in the Analogy We wish more power to the Alembic between Solutions and Gases," the other Club, and we wish for mare of its valuable by Arrhenius "On the Dissociation of reprints. Substances in Aqueous Solution," both of L. DAVIS TBNNEY which originally appeared in 1887 in the MASSACAUSRTTS I N E T I ~ U T08 B TBCANOLOCY CAMBRlDCB. MASSACHUSHTTS first volume of the Zeitschrijt fiir physikali s d e Chemie. Arrhenius had previously published in the Proceedings of the Soedish Academy of Sciencer for 1883 a paper on the conductivity of electrolytes and van? HOE in 1885 had Dublished in the same rare gases are given rather full treatment. One navel feature worthy of commendation is that radioactivity is taken up before atomic structure. On the whole the book is well arranged and subject matter placed in its logical position. An apparent digression from this is that the chapter on electrochemistry is placed between the tin and arsenic groups in the discussion of metals. I t is noted also that while electronic structure is taken up before the chapter on oxygen, oxidation receives only its usual discussion under "oxygen" and its more full meaning is given in a latter part. The book is nicely bound and printed in large clear type with only a very small amount of material in small type. From the standpoint of both the student and teacher this bwk should be well received. It is well arranged for study and assignment purposes. E. WHITE CHARLUS
