50 



SCIENCE 



[N. S. Vol. LIII. No. 1359 



iron anode and cathode with an asbestos cloth dia- 

 phragm. A brief summary of results which have 

 been obtained when operating on a commercial 

 scale when using this method is given, and the 

 advantages of operating in this manner as com- 

 pared with the customary procedure are empha- 

 sized. 



Estimation of ienzene in admixtwe with paraffin 

 Jiydro-carbons : H. McCormack. There is a con- 

 siderable quantity of material being used to-day, 

 particularly for motor fuels, which consists of a 

 mixture of benzene and its homologues with gaso- 

 line. This has emphasized the desirability of se- 

 curing a satisfactorily rapid and accurate method 

 of estimating the quantity of benzene which may 

 be present in such admixtures. Considerable study 

 has been given this question by various observers 

 and most of the properties of the compounds which 

 may be present in such admixtures have been 

 utilized from time to time in attempting such 

 estimation. The methods which have heretofore 

 been employed may be separated in two divisions. 

 The methods of accuracy which are long and 

 tedious, and methods of little accuracy which will 

 be used in a short time. This paper describes a 

 method by which the benzene is estimated from 

 the quantity of bromine absorbed in the forma- 

 tion of di-brom benzene. Further work is in 

 progress to determine the possibility of applying 

 the method to estimation of commercial benzol in 

 commereial gasoline where we will have present 

 not only benzene and parafSn hydro-carbons, but 

 also toluene, xylene, and other benzene derivatives. 



The permanganate determination of sulfur di- 

 oxide: H. S. CoiTH and James E. Withrow; The 

 action of permanganate upon sulfur dioxide and 

 sulfides: F. C. Vilbrandt and Samuel L. Shene- 

 riELD and James E. Withrow; and The iodometric 

 determination of sulfur dioxide: Gordon D. Pat- 

 terson and James E. Withrow. These three 

 papers represent a study on various phases of the 

 determination of sulfur dioxide from sulfuric acid 

 plant and smelter fumes. The permanganate re- 

 action with SO2 proves to be the exception to the 

 rule that permanganate goes to the MnO stage of 

 oxidation in presence of sulfuric acid and sulfites 

 going in part only to the MnO^ stage, as is fa- 

 miliar in alkaline reactions. We have found in 

 the case of the iodometric method which has 

 proved satisfactory in the Marsden modification 

 used by the Selby Smelter Commission that it can 

 be applied also to high concentrations of sulfur 

 dioxide if the color matching is not brought back 



to the original iodine color but the blank color 

 brought down by thiosulfate to the end color of 

 the SO2 specimen. 



Uniform paoTcages for reagent chemicals: W. D. 

 Collins. In order to secure better service in de- 

 liveries of reagent chemicals and to decrease the 

 possibility of contamination in packing the fol- 

 lowing suggestions are made. (1) A set of stand- 

 ard sizes of packages for each reagent chemical 

 should be adopted by the American Chemical So- 

 ciety. Ou« fairly large and one small size would 

 suffice for most reagents. Five hundred grams and 

 either 100 or 25 grams would probably be se- 

 lected. (2) Eeagents should be sold by weight in 

 grams. (3) Purchasers desiring reagents packed 

 in other than standard packages should expect to 

 pay proportionately more than for the standard 



Uniform specifications for chemical thermom- 

 eters: E. M. WiLHELM. 



Becovery of industrial gases with activated char- 

 coal: O. L. Baenebet. 



Evidences of auto-catalysis in the hydrogeration 

 of cotton seed oil: O. E. Sweeney and Joseph 

 Ellert. a series of experiments are given which 

 were carried out to establish the best hydrogera- 

 tion conditions using cobalt as the catalyzer. The 

 shape of the curve (slope) indicated that auto 

 catalysis was effecting the results. Experiments 

 were made which seem to bear this out. Since this 

 has never been observed, as far as we can learn, it 

 would seem to be a matter of the utmost impor- 

 tance in view of the very considerable amount of 

 research work being done along this line at pres- 

 ent. 



The use of ammonia oxidation to replace nitre 

 in cliamher plants: Charles L. Parsons. The 

 large saving which is to be made by the use of 

 ammonia oxidation instead of producing nitric 

 acid in the ordinary way where the oxides of ni- 

 trogen are to be used in a gaseous form has al- 

 ready been pointed out by the author in the 

 Journal of Industrial and Engineering Chemis- 

 try, Volume 11, page 451, 1919. On the recent 

 trip to Europe a study was made of the practise 

 in those countries, and it was found that am- 

 monia oxidation was rapidly replacing any other 

 source of oxides of nitrogen. In Germany this 

 method was used almost exclusively, while in Eng- 

 land some thirty plants have already adopted it, 

 and no plant which has adopted it has changed 

 back to niter. The plants which were visited and 



