May 15, 1903.] 



SCIENCE. 



785 



energy — an exhaustive study of oxygen is 

 taken up, introducing the subjects of combus- 

 tion, thermo-chemistry, the laws of Boyle and 

 Gay-Lussae, absolute zero, liquefaction of 

 gases, and closing with the experimental dem- 

 onstration of the statement that ' the real 

 difference in the properties of oxygen and 

 ozone is due to the different amounts of in- 

 trinsic energy present in their molecules.' 



The next chapter, on hydrogen and water, 

 leads to the phase rule and electrolytic dissocia- 

 tion. The following chapters on determina- 

 tion of atomic and molecular weights contain 

 also dissociation, the law of mass action, and 

 the freezing and boiling point methods. Next 

 comes an important chapter on osmotic pres- 

 sure and the theory of electrolytic dissociation, 

 written with excellent clearness. The con- 

 . ductivity method is here described. A chapter 

 on chlorin brings up the conception of acids, 

 of valence and Faraday's law. The subject 

 of valence, or valency as the author calls it, 

 has evidently been a diificult one to deal with. 

 There is clearly an effort to confine valence 

 solely to the ions, and structural formulas are 

 completely tabooed throughout the book. It 

 would be rather rash to cut loose from struc- 

 tural formulse in organic chemistry, but if 

 they represent a truth in one field, they repre- 

 sent a similar truth in the other. It is true 

 that structural formute have been fearfully 

 misused and abused in inorganic chemistry, 

 but this is no reason for completely abandon- 

 ing their use and confining valence to the ion 

 alone. The author is quite consistent, but he 

 has thrown away a useful piece of scaffolding 

 before the walls of his building are complete. 



The periodic system is the next topic, and 

 is well treated. We can not help thinking 

 that some of the imperfections which the 

 author finds would disappear if Venable's 

 modification of the table were used. This is 

 particularly true of the difficulty in making 

 sodium a member of the copper, silver, gold 

 group, and that of grouping fluorin with 

 manganese instead of with the halogens, where 

 it evidently belongs. 



From this point on, the elements are studied 

 in the order indicated by the periodic table. 

 The other halogens are followed by sulfur. 



under which the temperature-pressure diagram 

 is considered, and, in connection with hydro- 

 gen sulfid, reversible reactions. After nitro- 

 gen comes a chapter on neutralization of acids 

 and bases, and another on the atmospheric 

 air, including the inert gases. Under carbon 

 dioxid we find a discussion of critical tem- 

 perature and the continuity of the liquid and 

 gaseous states, as well as a brief outline of 

 the kinetic theory of liquids. The section 

 on the role of carbon in producing light is 

 particularly good. 



After completing the metalloids (the author 

 uses this term very sparingly, and the term 

 non-metals not at all, as far as we have 

 noticed), the metals are taken up, beginning 

 with those of the alkalies. The purification 

 of sodium chlorid gives occasion for a consid- 

 eration of the application of the law of mass 

 action to ions, and the sodium halids are used 

 to show the transition point on their solubility 

 curves. The phase rule finds a good illustra- 

 tion in the dissociation of calcium carbonate. 

 Tinder zinc is an extended discussion of pri- 

 mary batteries and solution tension. That 

 the book does not overlook practical applica- 

 tions of the subject is evidenced by nearly 

 two pages on phosphate fertilizers and their 

 analysis, and by a clear, if brief, treatment 

 of iron and steel manufacture. Iron also 

 leads to a consideration of oxidation as a 

 method of ion formation, and of chemical 

 action at a distance. Change of color with 

 change in electrical charge is exemplified by 

 the iron cyauids, and the color of ions by the 

 permanganates. Under uranium, radio-ac- 

 tivity is taken up, and under copper, ion 

 formation in substitution reactions. Pho- 

 tography is outlined under silver; gold fur- 

 nishes an example of ion foiination from 

 contact of molecules and also of colloidal 

 solutions. This last subject is more fully 

 taken up under platinum, where the work of 

 Bredig is noticed. 



We have thus gone rather minutely over 

 the contents of the book because it represents 

 somewhat of a pioneer attempt to treat inor- 

 ganic chemistry from the standpoint of phys^ 

 ical chemistry, and this necessitates present- 

 ing a pretty full outline of physical chemistry 



