84 



SCIENCE 



[Vol. LVI, No. 1438 



changer was in use one and one half years before 

 a tube was corroded badly enough to give away. 

 Recent developments in the methods for the 

 extraction of gasoline from natural gas: Fred E. 

 HosMER and P. M. Seibert. The commercial 

 importance of the natural gas gasoline industry 

 is reviewed. The chemistry of natural gas is 

 briefly discussed. Two new methods of gasoline 

 extraction are described. The first is known as 

 the low pressure evaporation method, in which the 

 crude product is utilized to furnish refrigeration 

 for cooling the gas after being subjected to 

 pressure. The second method is known as the 

 crude oil absorption method. This method con- 

 sists in subjecting the gas to about fifty pounds 

 pressure, at ordinary temperatures, and absorbing 

 the gasoline in crude oil, carrying the saturation 

 to about 25 per cent. 



Petroleum education: Edwin De Bare and 

 Fred W. Padgett. A survey of petroleum educa- 

 tion from the standpoint of pedagogy and prac- 

 tical application throughout the course of several 

 years. The paper is outlined as follows: I, Rela- 

 tion of the various branches of engineering to the 

 petroleum industry; II, Theoretical discussion of 

 petroleum education; III, Petroleum education at 

 the University of Oklahoma; IV, The future of 

 petroleum education. The writers reaBze that the 

 subject of petroleum education, especially from 

 the standpoint of chemistry, is in a formative 

 stage and it is hoped that the present paper will 

 stimulate discussion and that outlines of courses 

 in other institutions will be presented. 



Sulfur compounds a7id the oxidation of petro- 

 le.-um oils: C. E. Waters. In general, mineral 

 lubricating oils which contain large percentages 

 of sulfur compounds are more easily oxidized 

 than those in which there is less sulfur. This is 

 true whether the oils are heated to 250° C, as in 

 the oxidation method for determining the ' ' car- 

 bonization values" of oils, or when the oils are 

 exposed to sunlight. The precipitates formed on 

 diluting the oxidized oils with petroleum ether 

 contain higher percentages of sulfur than the 

 original oils. The residues left behind on crack- 

 ing and partially distilling off oils, as in the 

 Conradson carbon residue test, tend to retain the 

 sulfur in the oil. The bearing of these facts 

 upon the formation of sludge in transformer and 

 turbine oils and of carbon in internal combustion 

 engines is pointed out. 



DIVISION OF water, SEWAGE AND SANITATION 



A. M. Buswell, chairman 

 W. W. Skinner, secretary 

 The effect of temperature on the rate of reac- 



tion in water softening hy the lime-soda ash 

 method: Edward Bartow, M. E. Flentje and 

 W. U. Gallahek. 



Observations on the mechanism of iron re- 

 moval: A. M. Buswell. 



Specific gravity of mineral waters hy calcula- 

 tion: J. W. Sale. 



Bottled mineral waters of unusual composition: 

 W. "W. Skinner, C. H. Badger and J, W. Sale. 

 The composition of the domestic and foreign 

 bottled mineral waters examined in the water ajid 

 beverage laboratory of the Bureau of Chemistry 

 during the last fifteen years is discussed with 

 particular reference to the presence of unusual 

 constituents or of ordinary constituents present 

 in unusual amounts. The majority of these waters 

 belong to one or another of the three following 

 types: First, those in which the dissolved min- 

 eral constituents consist chiefly of dissolved lime- 

 stone or of dolomitie limestone; second, of sodium 

 bicarbonate and sodium chloride; third, of either 

 or both sodium sulfate and magnesium sulfate. 

 Usually a determination of the acid radicals, 

 namely, nitrate, chloride, sulfate, carbonate and 

 bicarbonate, and of the basic radicals, iron, alum- 

 inum, calcium and magnesium, together with a 

 calculation of the sodium by difference, will fur- 

 nish sufficient knowledge as to the' composition 

 of a water, provided qualitative tests are made 

 for the more unusual constituents. I •dinarily, 

 constituents other than those mentioned and silica 

 are present only in traces. There have been some 

 exceptions to the above, and instead of traces 

 only substantial amounts of certain constituents 

 enumerated below were found. The following 

 maximum amounts of constituents expressed in 

 milligrams per liter are reported : nitrate, 5700. ; 

 nitrite, 10. ; hydrogen sulfide, 496. ; bromide, 

 1510. ; iodide, 30. ; fluoride, 0.4 ; phosphate, 

 32950.; borate, 2000.; saline ammonia, 69.; 

 lithium, artificial water, 288. ; natural water, 32. ; 

 strontium, 200. ; barium, 18. ; manganese, 50. ; and 

 arsenic, 15. The composition of the so-called iron 

 and alum waters is discussed briefly. 



Two instances in which acute troubles were ex- 

 plained Vy means of the Pjj determination: W. P. 

 Monport. 



Hydrogen ion concentration and coagulation: 

 W. D. Hatfield. For the majority of water 

 works laboratories Gillespie's method for deter- 

 mination of Pjj values, without buffer solutions, is 

 most applicable. The amount of alum required 

 for coagulation of a water is dependent on the 

 buffer value of the water or the methyl orange 

 alkalinity. Turbidity has very little effect. 

 Coagulation begins at a p^j of 7.6-7.8 and the 



