Fhbruabt 24, 1922] 



SCIENCE 



217 



were produced by the explosion method when air 

 was used as the oxygen supply. When mixtures 

 of air and oxygen were used as the oxygen supply 

 in the explosion method appreciable quantities of 

 oxides of nitrogen were produced which are too 

 large to be disregarded in gas analysis. The 

 method used for determining the quantity of 

 oxides of nitrogen produced was a modification of 

 the di-phenol sulphonio acid method as used in 

 water analysis. 



The present status of methods used for fuel 

 gas analysis: G. W. Jones. The constituents 

 present and difficulties encountered in the accu- 

 rate analysis of fuel gases are given. The meth- 

 ods used at the present time, considerations 

 which must be taken into account in choosing a 

 particular method, the comparative accuracy of 

 the diiferent methods and debatable points which 

 require further consideration are discussed. 



Electric heat for thermal processes: E. F. 

 Collins. 



Sumidity equilibria of various common mate- 

 rials: KoBEET E. Wilson. A knowledge of the 

 equilibrium amount of moisture held by various 

 materials as a function of the relative humidity 

 of the air is very important for a variety of 

 purposes. The author presents determinations by 

 a method previously described in the Journal, of 

 the humidity equilibria of the following mate- 

 rials: cotton, linen, paper, jute, hemp, viscose 

 silk, cellulose nitrate silk, cellulose acetate silk, 

 rubber, leather, feathers, catgut, tobacco, crack- 

 ers, bread, macaroni, etc.; and includes data 

 gathered from various sources on other materials, 

 such as wool, silk, paper half-stuffs, timber, flour, 

 etc. 



The frictional resistance to the flow of viscous 

 liquids through elbows: Eobebt E. Wilson, Wil- 

 liam H. McAdams and M. Seltzer. The fric- 

 tional resistance to the flow of liquids through 

 elbows has been the subject of a considerable 

 number of scattered experiments, but the results 

 are seldom expressed on any uniform basis and 

 in many cases the methods of measurement were 

 faulty. Furthermore, there is practically no data 

 on the frictional resistance to flow through elbows 

 for very heavy oils flowing in straight line mo- 

 tion. The authors present a series of data cover- 

 ing the whole range, from highly viscous oils to 

 water, and show that, while the customary rule 

 of assuming an elbow to be equivalent to thirty 

 or forty pipe diameters' length of straight pipe 

 holds very well over the whole region of turbulent 

 flow, the resulting correction is far too high in 

 the region of viscous flow, dropping to as low as 



two or three diameters for very viscous liquids 

 in small pipes. 



A fermentation process for the production of 

 acetone, alcohol and volatile acids from corn cobs: 

 W. H. Peterson and E. B. Fred. Corn cobs are 

 a possible raw material for the production of 

 acetone, ethyl alcohol, formic acid and acetic 

 acid. These products are obtained by fermenting 

 a sirup which is made from corn cobs by 

 hydrolysis with dilute suLfuric acid and contains 

 chiefly xylose. This crude xylose sirup is fer- 

 mented by Bacillus acetoethylicum under the 

 proper conditions of nitrogen, and phosphate 

 supply and hydrogen ion reaction. A continuous 

 fermentation is maintained by filling the con- 

 tainer with cinders to which the bacteria may 

 attach themselves. The fermented solution is 

 removed and a new sugar solution added without 

 disturbing the bacteria. Under these conditions 

 the fermentation is rapid and vigorous. The 

 yield of products is 2.7 lbs. of acetone, 6.8 lbs. of 

 alcohol and 3.4 lbs. of acid per 100 lbs. of corn 

 cobs. 



A new method of preparing sulphuric acid: 

 P. C. Haeseler. Instead of oxidizing SO, 

 with the oxide of nitrogen, selenium dioxide 

 is used according to the equation: 2S0, + H O 

 + ^2^®°3 ~ 2H^SO^ -f Se. The selenium ^s 

 filtered and reoxidized. A 50 per cent sulphuric 

 acid free of selenium can thus be obtained 

 without pressure. Anode slimes and other im- 

 pure selenium sources can be used for the source 

 of selenium, as roasting the same will yield an 

 oxide sufficiently pure for the above reaction. 



Corrosion under oil films and the protective 

 action of certain colloidal solutions: Wilbert J. 

 Huff. An investigation by the writer in the 

 research laboratories of the Bureau of Mines on 

 the subject of corrosion beneath oil films caused 

 by water soluble salts from perspiration residues, 

 sea sprays, and certain manufacturing operations. 

 Preliminary treatment with water, followed by a 

 suitable emulsion, and finally by oil is recom- 

 mended for inaccessible surfaces. Experiments 

 are given to show the valuable anti-corrosive 

 property of certain soap emulsions, and some of 

 the conditions under which this protective prop- 

 erty fails. The mechanism of the corrosion and 

 protection is discussed briefly. 



On the dehydration of tar and other organic 

 emulsions: Wilbert J. Hupp. A note discussing 

 some of the methods for the dehydration of tar 

 and similar emulsions, pointing out a few ad- 

 vantages and disadvantages of each, together 

 with a description of a method suggested by the 



