130 PEOCEEDINGS: CHEMICAL SOCIETY 



Study of changes taking place in the conversion of cider into vinegar: 

 L. M. ToLMAN The conversion of a large quantity of cider into vinegar 

 was followed in a large factory in Michigan. The only important 

 change that occurs is the conversion of the alcohol into acetic acid, the 

 other substances present remaining nearly the same. The raw mate- 

 rial, altho varying from year to year, is remarkably uniform in com- 

 position in a given year. No general conclusions can be drawn from 

 analyses of home-made vinegars, which vary quite widely. 



In the discussion by Gore the fact was brought out that the yield is 

 about 73 per cent of the theoretical. Alsberg and Seidell also dis- 

 cussed the paper. 



Potassium ammonomagnesate and •potassium a?nmonoharate: E. C. 

 Franklin. The ammonia system of acids, bases, and salts was out- 

 lined, and the analogy carried on into the amphoteric compounds of 

 zinc, lead, etc. But cuprous copper, thallium, barium, and magnesium 

 also act as amphoteric elements in the ammonia system, and the salts 

 named in the title are among those recently prepared. The speaker 

 showed the apparatus and described the methods of manipulating these 

 compounds. £)iscussion by Foster, Johnston and Cameron. 



The 218th regular meeting was held on November 14, 1912, and 

 was devoted to the election of officers for 1913 as follows: President, 

 C. E. Waters, Bureau of Standards; First vice-president, M. X. Sulli- 

 van, Bureau of Soils; Second vice-president, C. L. Alsberg, Bureau 

 of Plant Industry; Secretary, R. B. Sosman, Geophysical Laboratory; 

 Treasurer, F. P. Dewey, Bureau of the Mint; Councilors, C. L. Als- 

 berg, Bureau of Plant Industry; S. F. Agree, Johns Hopldns Univer- 

 sity; P. H. Walker, Bureau of Chemistry; J. A. Le Clerc, Bureau of 

 Chemistry; Executive Committee, J. Johnston, Geophysical Labora- 

 tory; E. W. BouGHTON, Bureau of Chemistry; R. C. Wells, Geological 

 Survey; E. C. McKelvy, Bureau of Standards. 



Robert B. Sosman, Acting Secretary. 



The 219th meeting was held jointly with the Baltimore Branch of 

 the American Chemical Society in Hokpins Hall, Baltimore, on No- 

 vember 30, 1912. The following papers were read: 



The inflammability of coal dust: J. C. W. Frazer. Discussion by C. 

 Caspari, Jr., W. A. Randall, B. F. Lovelace, Marshall, Roundtree, and 

 J. A. LeClerc. 



The United States Pharmacopoeia, its origin, history and requireme7its: 

 Charles Caspari, Jr. Discussion by Englehardt and Le Clerc. 



C. P. Van Gundy, Secretary pro tem. 



The 220th meeting of the Chemical Society was held 12 December, 

 1912, at the Cosmos Club. President-elect C. E. Waters was elected 

 vice-president of the Washington Academy to represent the Society. 

 The following papers were read: 



R. B. Dole of the Geological Survey: The concentration of mineral 

 loaters in relation to their therapeutic activity. The efficacy of the waters 



