N e w Books
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also t h a t free use is made of the theorem of Le Chatelier and of the electrolytic dissociation theory. It is fairly evident t h a t more and more physical chemistry is being introduced in the elementary courses both in Belgium and in America. On p. 616, the author apparently considers lead acetate purely a s a catalytic agent in the conversion of lead into white lead by the Dutch process. ilccording to this view, the white lead is formed by the action of carbon dioxide upon lead hydroxide. If this is the case, i t would account for the excellent properties of t h e white lead made b y this process; but i t ought also b e very easy t o duplicate the results by a quicker method. TVilder D. Baizcrojt Ueber die Schichtungen bei Diffusionen. E i n e Vori~iitersuchzilzg. B y R a p h a e l Ed, Liescgnng. 14 X 22 c m ; pp. ,jj. Leipzig: II~illieliiz Eizgelmaiin, 1907. Price: p a p e r , 1.60 nzarks.-The author found great difficulty in repeating his earlier experiments on the ring-shaped deposits of silver chromate formed when silver nitrate is allowed to diffuse into a gelatine film containing potassium bichromate. A long series of experiments finally brought out the fact that the chief variable Jvas the quality of the gelatine. If the gelatine film nere alloived to age for several days, marked differences in the arrangement of the rings were obtained. It is n o t primarily a question of the viscosity of the gelatine. b u t depends rather on the hydrolytic decomposition of the gelatine. Using the figures a s a method of testing, i t n a s found t h a t the gelatine rvas not the same a s a commercial sample of glutine. W i l d e r D . Ba ncrojt Trait6 complet d' Analyse chimique appIiqi& a m Esseis indusfriels. B y J . Post aizd B . .Yeihiizaizii. D e i i r i h c bditioit j r a n p i s e enti2rwtent rejoitdne. Tradicife d'lipr6s la troisi2ine tditioia nllenzaizdc et aiLgiiaentc'e de nonzbrt.user a d d i tions pav L . Gauticv. Toirie pvcmicr, preinicr jasciczile. Prix, 6 jr, 50.--The complete work is to consist of t v o volumes, each having four parts. The present number is the first of volume one. I t deals with water, combustibles, pyrometry, a n d gas. The chapter on pyrometry is the one which \Till appeal the most to the physical chemist and is a n excellent one. I n the pages on the optical pyrometers we find a discussion of the instruments of Le Chatelier, IVanner, Fkry, Holborn and h u r l b a u m (Morse patent), Il.ildcr D . Baizcrojt
Les Rayons Cathodiques. Bj,P. \'illard. (C'ollcctioii S c z e n t i a . ) U c ~ii idiize L(ilitioi2. 13 x 2 0 cm; pp. IO;.. P a r i s : Gaiitiiicr-I'illars, 1908. ~ v i r c :l i n e n , z jrancs.-The
subject is treated under the headings: apparatus; electrical phenomena in rarefied gases; cathodic emission ; electrification of the glass tube ; properties of cathode rays; X-rays; electrification of cathode rays; electrostatic effects; action of a magnetic field on cathode rays; velocity of cathode rays; heterogeneity of cathode rays; chemical action of cathode rays; diverse phenomena ; formation of cathode rays. The last two pages of the book are devoted to a discussion of the nature of radiant matter. "In the first edition of this book we supposed that the cathodic coqiuscles were electrified particles of hydrogen. --It that time electricity was considered a s inseparable from matter and this hypothesis therefore seemed almost necessary, especially as i t explained perfectly the reducing action of the rays and the constant presence of hydrogen a t the cathode.
