abstracts: entomology 79 



INORGANIC CHEMISTRY.— r/z^ equilibrium between carbon mon- 

 oxide, carbon dioxide, sulfur dioxide, and free sulftir. John B. 

 Ferguson. Journ.Amer.Chem.Soc. 40: i 626-1 644. November, 

 1918. 



This paper contains an extended account of the investigation of the 

 reaction CO + V2SO2 < ^ CO2 + V4S2, a partial summary of which 

 appeared last year. The study was undertaken primarily as a part 

 of a comprehensive study of certain gas reactions and their r61e in vol- 

 canic activity, and this particular reaction was selected because it af- 

 forded a direct means of determining the free energy or thermodynamical 

 potential of sulfur dioxide, one of the most important of the volcanic 

 gases. 



The composition of the equihbrium gas mixtures obtained, with the 

 corresponding initial gas mixtures, both calculated and actual, and the 

 resulting equilibrium constants, are given in tabular form and the ther- 

 modynamical calculations based thereon given in detail. The latter 

 give an average mean value of 3 . 99 for the thermodynamical constant 

 I and — 22510 calories for the change in free energy for the reaction 

 under standard conditions. For the reaction Sr + O2 < ^ SO2 under 

 similar conditions, the value for the change of free energy is - 69761. 



R. B. SOSMAN. 



UNTOMOhOQY. —Memoirs on the Coleoptera VIII. Thomas L. 

 Casey. New Era Printing Company, Lancaster, Pa. November 

 12, 1918. 



In this volume the author reviews several large subfamilies of the 

 Carabidae or ground beetles. A very large number of new species and 

 subspecies are described, especially in some of the groups of the Bembi- 

 diinae and in the Celia and Amara of the Amarinae. A r^sum^ of the 

 American genera and subgenera of the Pterostichinae is given in some 

 detail. There can scarcely be a doubt that all the forms enumerated 

 have at least some taxonomic standing, although the true interrelation- 

 ship of the various units is a problem that cannot be solved except 

 in many years of careful study. 



There are two passably definite methods in the investigation of 

 natural groups in the Insecta, so far as the delimitation of species is 

 concerned. One of these methods, which is more especially developed 

 among the German investigators, constantly bears in view the over- 

 looking of differences, in order to reduce specific forms to the smallest 



