Chemistry and Physics. 221 



(4) and (5). By whatever method produced, the density of the 

 amorphous carbon was always less than two, that of the purest 

 non-ignited lampblack being 1*76. Amorphous carbon polymer- 

 izes on heating, thus raising its ignition point in oxygen and its 

 resistance to chromic acid solution. 



The second paper treats of graphite, the samples considered 

 being from Ceylon, Borrowdale, Ticonderoga, Greenville, 

 Omeansk, Mugrau, Scharzbach and Karsok ; and also from an 

 American pegmatite, and the Blue Earth from the Cape. The 

 carbon in meteorites is considered, and also that separated from 

 iron. The densities, the ignition points and the rates of oxidation 

 of artificially prepared samples are discussed and the displace- 

 ment of carbon in lused cast-iron by boron and silicon is con- 

 sidered. The preparation and properties of intumescent graphite 

 are also described. 



In the third paper, the diamond is taken up, and its properties 

 are given and the composition of the ash left on combustion. 

 The occurrence of diamonds in the Blue Earth from the Cape, in 

 sand from Brazil and in the Canon Diablo meteorite is discussed ; 

 and then the author passes to consider the solubility of carbon in 

 various metals at ordinary pressures, and the formation of definite 

 carbides, as well as the effect of high temperatures on different 

 forms and the properties of carbon vapor. Numerous experi- 

 ments are described on the artificial production of diamonds and a 

 description is given of the method used for the combustion of 

 artificial diamonds. — Ann. Chim. Phys., VII, viii, 289-305, 306- 

 347, 466-558, July, Aug., 1897. g. f. b. 



6. Die WissenschafUichen Grundlagen der Ancdytischen 

 Chemie. ; Elemental- dargestellt von W. Ostwald. Zweite ver- 

 mehrte Auflage, 12mo, pp. x, 200, Leipzig, 1897 (Engelmann), 5 

 marks. — This book, like all of Ostwald's writings, has been 

 remarkably well received by chemists; so much so that a new 

 edition has been called lor in less than three years. It treats of 

 the scientific basis of analytical chemistry in the light of the 

 more modern views of physical chemistry of which its author is 

 so distinguished an exponent It is divided into two parts, the 

 first being theoretical and the second practical. The subjects 

 treated in the first part are the detection of substances, the sepa- 

 ration of substances in the solid, liquid and gaseous states, physi- 

 cal separation-methods, chemical methods of separation, and the 

 measurement of substances. The second part treats of the appli- 

 cation of these principles to the detection and estimation of sub- 

 stances, the first chapter considering acids and bases, the second 

 the alkali metals, and so on, ending up with chapters on the 

 non-metals and on the calculation of analyses. The most im- 

 portant chapter in the book seems to us to be that on chemical 

 separation methods, in which is considered the modern theory of 

 solution, including Van't Hoff's theory of osmotic pressure and 

 Arrhenius' theory of electrolytic dissociation, according to which 

 " salts do not exist as such in aqueous solution but are more or 



