49-t Scientific Intelligence. 



reference to its Oxygen Content ; by Francis G. Benedict. 

 Pp. 115; one plate. This investigation confirms the conclusion 

 as to the essential constancy in the oxygen percentage of outdoor 

 air. The experiments extended over a period of nine months, 

 during which this constancy was maintained through all changes 

 of the weather as to air-pressure, temperature, humidity, and 

 other important conditions. The average of 212 analyses of air 

 from near the Nutrition Laboratory showed 0'031 per cent of 

 carbon dioxide and 20'938 per cent of oxygen ; observations over 

 the ocean gave respectively 30-936 per cent (Montreal-Liverpool, 

 7 anal.) and 20*932 per cent (Genoa-Boston, 36 anal.) ; while at 

 Pike's Peak the result was 20'927 per cent (9 anal.). The extra- 

 ordinary rapidit3 r with which local variations, for example, in a 

 city, are equalized was shown by observations on street air, whicb 

 indicated but a slight trace of oxygen deficit ; even in the Boston 

 subway at 9.30 A. m., the only changes were a rise of the carbon 

 dioxide to "065 per cent and a' fall of the oxygen to 20-897 per 

 cent. 



No. 167. A Bicycle Ergometer with an Electric Brake ; by 

 Francis G. Benedict and Walter G. Cady. Pp. Ill, 44, with 

 16 figures. 



2. British Association for the Advancement of Science. — The 

 eighty-second meeting of the British Association was held at 

 Dundee during the week beginning with September 4 ; the 

 registration at the opening reached tbe large number of 2379 

 members. The address of the President, Professor E. A. Schafer, 

 on the "nature, origin and maintenance of life," has attracted 

 much attention. 



3. Introduction to Agricultural Mycology. 1. Soil Bacteri- 

 ology ; by Dr. Alex. Kossowicz. Pp. 143, 47 illustrations. 

 Berlin, 1912 (Gebriider Borntraeger). — This is the first of two 

 volumes by the author on agricultural mycology. It consists of 

 four parts : The role of the elements (C, O, H, N, S, P and Fe) 

 under the influence of micro-organisms; the mycology of the 

 soil; tbe mycology of manure; and the influence of the micro- 

 flora on the soil. The book abounds in literary references, which 

 alone should make it a valuable publication. It is a thorough 

 compilation of important data. Special emphasis is placed on 

 the chemical changes which take place in the soil through the 

 agency of moulds and the lower and higher forms of bacterial 

 life. The book should prove to be of much value to the student 

 of soil chemistry and bacteriology. l. e. r. 



4. Catalogue of 98J/.2 Stars, or all Stars very conspicuous to 

 the naked eye, for the Epoch of 1900 ; by W. T. Backhouse, 

 West Hendon House Observatory. Pp. xx, 186, 4to. Sunderland, 

 England (Hills & Co.). — This very handsome volume is pub- 

 lished to accompany a set of 14 large stars maps on the gnomonic 

 projection (a projection from the center of the sphere onto planes 

 tangential to the surface). The whole work is designed for use 

 in observations of meteors, and the greatest care has been exer- 



