June 4, 1921 abstracts: analytical chemistry 261 



Sderospora spontanea on the wild Sacchanmi spontaneume is regarded as 

 evidence that the disease has passed and is passing from this native host to 

 introduced maize. W. H. W. 



ENTOMOLOGY. — The North American ichneitmon- flies of the tribes Lycorini, 

 Polysphinctini, and Theroniini. R. A. Cushman. Proc. U. S. Nat. 

 Mus. 58: 7-48. PI. 2. 1920. 



This paper adds another to the series of papers revising the American 

 tribes of the subfamily Ichnenmoninae {Pimplinae). In it the genera and 

 species are tabulated and described, and notes on the location of the types, 

 biology of the species, and other valuable taxonoraic information given in 

 detail. As is usual for papers of this series, the host list and an index of the 

 species treated is included. Several text figures illustrating the structural 

 characters and some drawings and photographs showing the habitus of the 

 insects are added. S. A. Rohwer. 



ENTOMOLOGY. — A^ew Serphidoid, Cynipoid, and Chalcidoid Hymenoptera. 

 A. A. GiRAULT. Proc. U. S. Nat. Mus. 58: 177-216. 1920. 



This paper contains descriptions of new parasites which have been received 

 for identification by the Bureau of Entomology. Most of the forms char- 

 acterized are from North America and some few of them are known to be of 

 considerable economic importance. S. A. Rohwer. 



ANALYTICAL CHEMISTRY.— 5«/p/z Mr in petroleum oils. C. E. Waters. 

 Bur. vStandards Tech. Paper 177. Pp. 28, fig. 1. 1920. 



Short accounts are given of the theories concerning the origin of the sul- 

 phur and sulphur compounds which are found in crude petroleum. The 

 forms of combination in which the element occurs, their identification and 

 significance are briefly discussed. Tests for the detection of sulphur are de- 

 scribed, and the copper test is shown to be one of great delicacy. Although it 

 will show the presence of very minute amounts of free sulphur or of hydrogen 

 sulphide, it may be of no value at all when the sulphur is in stable organic 

 compounds. Various methods that have been used for the determination of 

 sulphur in oils, and finally a new procedure, are described. The new method 

 is based on the preliminary treatment of the oil with nitric acid saturated with 

 bromine, followed by fusion with a mixture of sodium nitrate and carbonate. 



Data obtained by the analysis of certain oils by this and other methods 

 are given. From these it appears that there is no loss of sulphur by the new 

 method, which is recommended for laboratories which do not have a bomb 

 calorimeter. C. E. W. 



ANALYTICAL CHEMISTRY.— .4« electrolytic resistance method for de- 

 termining carbon in steel. J. R. Cain and L. C. Maxwell. Bur. 

 Standards Tech. Paper 141. Pp. 24, figs. 6. 1919. 



Method and apparatus are described for rapidly and accurately determining 

 carbon in steel by absorbing in a solution of barium hydroxide the carbon 

 dioxide resulting from direct combustion of the metal in oxygen, and deducing 

 the carbon content from the change in electrical resistance of the barium 

 hydroxide solution. J. R. C. 



