10 EXPEBIMENT STATION BECOBD. [Vol.88 



A useful distilling head, O. Steabns {Jour. Indus, and Engin. Chem., 9 

 (1917), No. 10, pp. 972, 973, fig. i).— A distilling head which has been found 

 useful for liquids which frotli easily or have a tendency to bump is described 

 by a figure. 



The separation of aluminum from iron by means of ether, S. Palkin {Jour. 

 Indus, and Engin. Chern., 9 (1917), No 10, pp. 951-95S).— The essentials of the 

 method described are as follows : 



The dried mixed chlorids of aluminum and iron are talien up In a small 

 amount of hydrochloric-acid-alcohol solution and evaporated to crystallization 

 of the salts. The residue is again acidified with alcoholic hydrochloric acid, 

 and ether which contains a trace of water gradually added. The aluminum 

 is precipitated as a hydrated chlorid varying in composition while the ferric 

 chlorid remains in solution. The precipitate is separated by filtration and the 

 aluminum precipitated from an aqueous solution of aluminum chlorid as the 

 hydroxid, filtered, ignited, and weighed with the usual precautions. The ether 

 solution of iron is distilled or evaporated to remove the ether, the residue trans- 

 ferred with a little water and hydrochloric acid to a weighed platinum dish 

 (using as little water as possible), and evaporated to dryness on the steam bath. 

 The residue is moistened with 1 cc. concentrated sulphuric acid, gently warmed 

 on the steam bath to expel most of the hydrochloric acid, and slowly heated 

 over a flame on an asbestos gauze until all the ferric chlorid is converted to 

 the sulphate. It is then heated over a free flame, and finally over the blast 

 lamp to convert the sulphate to ferric oxid. The oxid is cooled and weighed 

 in the usual manner. 



The procedure is described in detail, and analytical data submitted which 

 indicate the accuracy of the procedure. Essential data obtained in the study of 

 the effect of moisture, alcohol, and hydrochloric acid on the accuracy of the 

 method are also submitted. 



The determination of sulphur dioxid, O. R. Sweeney, H. E. Outcault, and 

 J. R. WiTHEOW {Jour. Indus, and Engin. Chem., 9 {1917), No. 10, pp. 949, 950). — 

 Data are submitted which indicate that potassium permanganate is to be pre- 

 ferred to iodin for the determination of sulphur dioxid. It gives as great ac- 

 curacy, is as easy to prepare, can be more easily manipulated, can be used for 

 traces as well as large amounts of sulphur dioxid, is more stable to light, gives 

 a color as easy or easier to match than the starch-iodin end point, and requires 

 no simultaneous blank, consequently less apparatus to be transported in the 

 field. 



The details of the manipulation of the method are the same as those of the 

 iodin method used by the Selby Smelter Commission (B. S. R., 34, p. 716). 



The effect of temperature on the reaction of lysin with nitrous acid, 

 B. SuEE and E. B. Habt {Jour. Biol. Chem., SI {1917), No. 3, pp. 527-532).— 

 Data are submitted by the authors, at the Wisconsin Experiment Station, 

 which show that at definite concentrations 32* C. is the lowest temperature 

 at which both amino groups of lysin react with nitrous acid in 5 minutes. At 

 certain definite concentrations 80° was the lowest temperature at which both 

 groups reacted with nitrous acid in 10 minutes. 



It is suggested that " at temperatures of 30° C. and above, 10 or a maximum 

 of 15 minutes would be more than sufiicient for shaking the hexone bases 

 In the Van Slyke method [E. S. R., 26, p. 22] of protein analysis, at any 

 concentration, instead of 30 as was the practice heretofore." It was found 

 possible to render the e-amino group of lysin entirely inactive at temperatures 

 of 1* and slightly below with certain definite concentrations. 



