Chemistry and Physics. 53 



mathematical presentation of physical chemistry, particularly 

 such aspects of it as lead up to and discuss the theory of elec- 

 trolytic dissociation or ionization in solution. Such topics as 

 physical and chemical equilibrium, ionic equilibrium treated 

 quantitatively, are also rather elaborately presented. The 

 author states that the book is designed for the use of students 

 who have had a rather thorough course in general inorganic 

 chemistry, and hence extended explanations of simpler processes, 

 interpretations of many elementary reactions, and almost all 

 equations have been omitted. He makes the further statement 

 that reference books of qualitative chemical analysis and gen- 

 eral inorganic chemistry are assumed to be available at all 

 times. The importance of instruction in physical chemistry is 

 admitted, but it may be questioned whether the student should 

 not first learn the facts connected with qualitative analysis and 

 afterwards apply them to the study of theories, rather than to 

 attempt to explain facts on the basis of theories ; for it is certain 

 that theories are based upon facts, not facts upon theories. A 

 course in qualitative analysis is usually employed as the best 

 opportunity to give the student of chemistry a thorough drill 

 in the writing of chemical equations. This feature is practically 

 neglected in the book under consideration. 



The book displays many good features, and is probably well 

 adapted for the use of certain classes of students, but it seems 

 doubtful that its plan of teaching qualitative analysis will be 

 widely followed. h. l. w. 



5. Factory Chemistry; by Wm. H. Hawkes. 12mo, pp. 59. 

 New York, 1921 (Longmans, Green and Co. Price $1.00 net). — 

 This very small text-book comes from the Department of Chem- 

 istry, Ford Institute of Technology, Detroit, Mich. It is said 

 to be intended for the use of "factory men interested in the 

 study of chemistry as it bears on the various operations in factory 

 processes, ' ' but an examination of the book fails to reveal any 

 such practical bearing. There are brief statements and defini- 

 tions of some of the principles, laws and terms of chemistry, but 

 the book is devoted chiefly to an explanation of valence in con- 

 nection with the writing of formulas and equations and to a 

 condensed outline of qualitative analj^sis. The attempt to teach 

 the writing of equations in connection with the laws of valence 

 alone appears to be unsatisfactory, for in one place, under the 

 heading ''Oxides and Acids=^ Salts and Water/' the student is 

 directed to complete the equations of a number of oxides, includ- 

 ing PbOs, SnOs, AsoOg and SbsOg with acids H2SO4, HNO3, 

 HCl, HC2II3O2, II2C63 and II3PO4. In these cases most of the 

 expected "salts" do not exist, or else the oxides do not dis- 

 solve in the acids, so that nearly all of the equations would rep- 

 resent impossibilities. There appears to be no information given 

 in the book as to the fact that many reactions are reversible, nor 



