328 Scientific Intelligence. 



acid SO a . H„0 be present also it nia3 r act similarly and the follow- 

 ing; mixed condensed anhydrides would be obtained; (S a O„) a . 

 (SO a ) a . (H a O) a which is tetrathionic acid; S a O a . (SO a ) 4 . (H a O) a 

 which is trithionic acid; (S a O a ) 4 . SO a . (H a O) a which is the acid 

 obtained when preparing pentathionic acid by the method of 

 Debus, in the first crystallizations; and (S a 2 ) 3 . (SO a ) 3 . (H a O)„, 

 an acid not yet isolated. Since the conversion of the thionic 

 acids into thiosnlphuric acid alone or into this acid and sulphur- 

 ous acid would involve an absorption of heat, the change does 

 not occur in acid solutions. — C. JR., cviii, 925-930 ; J. Chem. Soc, 

 lvi, 823, Sept., 1889. G. p. B. 



II Geology and Minekalogy. 



1. Geological Society of America. — Sessions of the Geological 

 Society were held at Toronto on Wednesday, August 28th, alter 

 the General session of the American Association, and also on 

 Thursday, August 29th. Professor James Hall was the president 

 of the meeting. Besides the address of the president and the 

 transaction of business connected with the organization of the 

 Society, papers were read as follows : J. D. Dana on the Areas 

 of Continental Progress in North America, and the influence of 

 these areas on the work carried on within them ; James Hall, on 

 the subdivision and grouping of species usually included under 

 the generic term Orthis, in accordance with external and internal 

 charactei's and microscopic shell structure, and on new genera 

 and species of the Family Dictyospongidae ; G. K. Gilbert, on 

 the strength of the Earth's Crust ; Joseph LeConte, on the 

 origin of normal faults and of the structure of the Basin region ; 

 T. C. Chamberlin, on Bowlder belts as distinguished from 

 Bowlder trains, their origin and significance ; C. D. Walcott, 

 study of a line of displacement in the Grand Canon of the Colo- 

 rado, Arizona ; J. F. Kemp, on Trap dikes near Kennebunkport, 

 Maine. Although the number of members enrolled exceeds one 

 hundred and fifty, and many of them were present, the sessions 

 for reading papers were restricted to Thursday in order -not to 

 interfere with the American Association. The Society adjourned 

 to meet in the city of New York on the 26th of December. 



2. North American Geology and Palaeontology. — This is the 

 title of a work, now in press, by S. A. Miller of Cincinnati. 

 The book will be in royal octavo and contain about 800 pages of 

 two columns each in brevier type. The first hundred pages is 

 devoted to Geology and the laws of nomenclature, then follows a 

 Catalogue of the American Paleozoic Fossils arranged in classes 

 with the genera in alphabetical order. Every genus is denned 

 and nearly all of them are illustrated and to a great extent by a 

 figure of the type species. Synonyms, preoccupied names and 

 those too poorly defined to warrant recognition are in italics. 

 Special attention has been paid to Classification so as to present 

 to view, at once, the existing state of our knowledge of the zool- 



