214 EXPEEIMENT STATION RECORD. 



again, allowed to settle, and decanted. The calcium carbonate precipitate is 

 then transferred to the filter, where it is washed free from chlorin. The calcium 

 is weighed as calcium oxid. 



Determination of sulphuric acid by the barium chromate method, M. Hol- 

 LiGER (Ztschr. Anahjt. Chem., J,9 {1910), No. 2, pp. S.'/-93 ) .— The neutral solu- 

 tion containing the sulphate is brought to boiling (carbonates, if originally 

 present, are destroyed by heating with acid), the acid barium chromate solution 

 (prepared according to Bruhn's method) is added, the solution is boiled again 

 for a minute or so, 1 or 2 drops of feri-ic chlorid solution is added, then am- 

 monia until the solution has a definite odoi", and finally the excess of ammonia 

 boiled off. The precipitate is allowed to stand and settle, the solution filtered 

 into a 800 cc. ground glass stoppered bottle, and the precipitate washed with a 

 little hot water. The filtrate is cooled quickly by immersing the bottle in run- 

 ning water, and 20 cc. of concentrated hydrochloric acid and 20 cc. of a 10 

 per cent potassium iodid solution are added. The solution is diluted to 400 cc. 

 and allowed to stand (stoppered) for 4 hour, when it is titrated with deci- 

 normal thiosulphate solution, using staix-h as an indicator. One cc. of deci- 

 normal thiosulphate equals 3.269 mg. of HiSOj. 



Method for determining carbon dioxid with the Berthelot bomb, E. Grafe 

 (Biochem. Ztschr., 2Ji {1910), No. 3-5, pp. 277-2S1). — The author proposes 

 estimating carbon dioxid in physiological chemical analysis by connecting a 

 valve to the bomb of a Berthelot calorimeter, which in turn leads to a U-tube 

 filled with calcium chlorid (previously saturated with carbon dioxid and then 

 thoroughly aerated), to 2 Geissler or Wetzel tubes containing 40 per cent 

 potassium hydrate and with a superimposed calcium chlorid tube on them, 

 and finally, to an additional U-tube which contains calcium chlorid and soda 

 lime to prevent any reverse external carbon dioxid from entering the apparatus. 

 The valve on the bomb is so regulated that the gases can pass over into the 

 saturating apparatus in small bubbles. The author also suggests utilizing this 

 method for determining the vapor tension at the same time. 



Behavior of protein solutions with acetone, T. Weyl {Ber. Dciit. Chem. 

 GeselL, .'i3 (1910). No. 3. pp. 508-511). — It is shown that with acetone a com- 

 plete precipitation of the total protein of cow's milk and blood can be obtained. 

 The method is shown to be very stitisfactory as compared with that of Hoppe- 

 Seyler. 



Determination of saltpeter in meats with nitron, C. Paal and A. Gang- 

 HOFER {Ztscln: Untcrsiich. Nahr. n. GenussmtL, 19 {1910), No. 6, pp. 322- 

 328). — Continuing previous work (E. S. R., 21. p. 702), the authors propose 

 digesting the meat extract with sodium hydrate solution in place of the pre- 

 liminary treatment with lead acetate, as recommended by Paal and Mehrtens 

 (E. S. K., 18, p. 52,-)). 



An application of the Folin method to the determination of the am- 

 moniacal nitrogen in meat, M. E. Pennington and A. D. Greenlee {Jour. 

 Amer. Chrm. Soc, 32 {1910), No. J,, pp. 561-568, fig. i).— The authors show that 

 unsatisfactory results are obtained in chicken meat by distilling off the am- 

 moniacal nitrogen by the usual method with the aid of magnesium oxid, and 

 they attempt to remove the ammonia directly from the tissue or tissue extract 

 by means of a modified Folin method. 



To evolve the ammonia, experiments were conducted with magnesium oxid 

 and sodium carbonate. With both reagents tlie same results were obtained. 

 The ammonia obtained from the extract was always somewhat less than that 

 obtained from the tissue itself. 



Analyses of chicken meat showed that perfectly fresh birds contained from 

 0.011 to 0.012 per cent of ammonia in the tissues. Those which were liept at 



