522 



SCIENCE. 



[N. S. Vol. XXII. No. 565. 



vania, Ohio, California and Texas crudes, 

 that we might expect. In the section on 

 ' Fermentation ' also we find no mention of 

 Buchner's great discovery of zymase in the 

 expressed liquid from comminuted yeast-cells, 

 which is now considered as the greatest ad- 

 vance in our knowledge of the action of the 

 yeast plant since the time of Pasteur. 



Part III., written for this edition by Charles 

 D. Demond, S.B., in the space of 54 pages, 

 gives a very excellent survey of metallurgical 

 methods, covering all the technically impor- 

 tant methods. 



The book is undoubtedly the best book of 

 its kind in the English language, covering 

 in one volume of moderate size an outline 

 of the manufacturing methods of technical 

 chemistry. Samuel P. Sadtler. 



Inorganic Chemistry, with the Elements of 



Physical and Theoretical Chemistry. By 



J. I. D. Hinds, Ph.D. Second Edition. 



New York, John Wiley & Sons. 1905. 



Large 8vo. Pp. viii + 651. 



This work, on its first appearance, was care- 

 fully reviewed in this journal; it seems neces- 

 sary, now, only to show in what respects the 

 present edition differs from the former. 



The plan of the book remains essentially the 

 same, but there has been an increase of eighty- 

 five pages, and the text has been revised. Sev- 

 eral chapters have been enlarged or rewritten, 

 and new chapters have been added. These 

 changes affect mainly ' Theoretical and Phys- 

 ical Chemistry.' The treatment of these sub- 

 jects is much better and fuller than in the 

 earlier edition, but unnecessary rules and 

 questionable statements may still be noticed. 

 Is it well that a student should write struc- 

 tural formulas of acids by the following rule: 

 ' Connect each hydrogen atom by an oxygen 

 atom to the negative, then connect the remain- 

 ing oxygen atoms, which are saturating, to 

 the negative by both points ' ? Is it correct 

 to say that ' the reaction of a salt is neutral ' ? 



Although blemishes like the above are still 

 too numerous, they are noticeably less than 

 they were in the first edition. The excellence 

 of the descriptive portion of the text is un- 



questioned, and the work in its present form 

 should win new friends. L. B. Hall. 



Haverford College. 



Cements, Limes and Planters, their materials, 

 manufacture and properties. By Edwin C. 

 Eckel, C.E., Associate, American Society of 

 Civil Engineers, etc.; Assistant Geologist, 

 U. S. Geological Survey. New York, John 

 Wiley & Sons. 1905. 



This is an exceedingly valuable and well- 

 nigh exhaustive work. It is by far the most 

 valuable work on the several subjects that it 

 treats that we have met, and in our judgment 

 may be rightly considered a masterpiece of 

 compilation. In the orderly and systematic 

 arrangement of sub-subjects in the several 

 parts and chapters the author's mastery of his 

 general subject is exhibited not only to his 

 own credit, but to the great pleasure and profit 

 of his readers; for next to the enlightening 

 information conveyed by an author comes the 

 proper unfolding of a subject through sys- 

 tematic arrangement. 



It is, however, as an engineer, of broad at- 

 tainments outside the field of engineering, 

 that Mr. Eckel addresses engineers. He does 

 not profess to be a chemist, the chemistry of 

 cements, limes and plasters is not mentioned in 

 his title, therefore he may be pardoned if in 

 the small space he devotes to the chemistry 

 of these substances he follows the well worn 

 path made by Mr. S. B. Newberry and Mr. 

 Clifford Richardson's committee, which for 

 some reason not clear to the general reader 

 leads direct to the manufacturers of cement, 

 leaving the interests of the users of cement 

 completely uncared for. Nothing else could 

 be expected, as Mr. Richardson's committee 

 has the floor, and that committee recommends 

 a method of chemical analysis that is ultimate 

 and that, so far as chemical analysis is con- 

 cerned, destroys the differences that exist in 

 very unlike cements. A cement that con- 

 tained five per cent, of uncombined silica and 

 fifteen per cent, of combined silica would show 

 twenty per cent, of silica on analysis by the 

 method recommended by Mr. Richardson's 

 committee, while a cement containing twenty 

 per cent, of combined silica would on ultimate 



