246 • THE AMERICAN CHEMIST. 



distinguishing characteristics of the substances classified." One such 

 group starts with Sb, 120-3; As, 75; P, 31; N, 14; Sn, 59, and Pb, 103-5. 

 Another comprises Hg, 200; Cd, 112; Zn, 65-5, and Mg, 24-4; all the 

 members of this last group are in one of Mendeleef's groups, and the 

 first four members of the first group are also in another of Mendeleef's. 

 This grouping is founded on a broader basis; but Lea's was published 

 thirty years ago, in 1800. 



Gibbs showed by reference to the volumetric relation of gaseous 

 compounds that if the i^roposed new atomic weights, 1(), 12, and 32, be 

 accepted for oxygen, carbon, and sulphur, the atomic weights of at least 

 fifty other elements must be doubled, and as he is not a man to fail to 

 give due credit to others it is fair to infer that he was the first to call 

 attention to this necessity. Lea's work on the ethyl bases, as he calls 

 them, diethylamine, triethylamine, etc., is comprised in several papers, 

 in which he gives a very full account of their reactions and a new 

 method of separating them by picric acid. Ordway gave a very exhaust- 

 ive paper on soluble glass, its chemistry and applications; Gibbs and 

 Lea also made extensive researches on the platinum metals, and very 

 notable are the many contributions made by Gibbs on improvements in 

 methods of analysis. Everything coming from his laboratory was reli- 

 able, and there was much of it. Hunt published three papers on the 

 chemistry of mineral waters, in Avhich, on the basis of certain general 

 principles laid down, and of a number of analyses of waters of the 

 Cham]»lain and St. Lawrence basins, lie attem}»ted to trace the history 

 of these waters and account for their origin, and in another pai)er he 

 attem])ted also to trace out the origin of the dolomites. Crafts, with 

 Friedel, by results of research on the silicic ethers, jiroved, as he thinks, 

 convincingly the tetratomic character of silicium. Gaffield's interest- 

 ing researches on the action of sunlight on glass were made in this 

 decade. Gibbs made a very va]ual)le contribution to the resources of 

 physical chemistry by a calculation of the wave lengths of the lines of 

 a large number of the elements, from measurements made by Angstrom 

 and Ditscheiner, and Iluggin's scale of wave lengths of 1,000 lines. 

 Goessmau discussed in a careful and thorough manner the origin of the 

 salt beds and the composition of the salt and the brine of the ocean 

 water. 



Three notable books appeared in this decade, Cooke's "Chemical 

 Physics," Storer's "Dictionary of Solubilities," and Wormley's "Micro- 

 chemistry of Poisons." 



In the seventies, about 240 papers were puldished, a part of them 

 in three new periodicals. The American Institute of jNIining Engineers 

 issued its first volume of Transactions in 1871. Methods of chemical 

 analysis naturally occupied mnch of the attention of the chemical mem- 

 bers ofthis institute. The Ameriean Chemical Journed and the Journal 

 of the American Chemical Society made their first appearance in 1879. 

 This society was established in 1877 and published two volumes of 



