504 EXPERIMENT STATION" RECORD. 



The enzyms of washed zymin and dried yeast (Lebedew): I, Carboxylase, 

 A. Haeden (Biochem. Jour., 7 {1913), No. 2, pp. 214-217) .—" Zjmm and dried 

 yeast (Lebedew) after being freed from coenzym by washing, and thus ren- 

 dered incapable of fermenting glucose, readily decompose pyruvic acid into 

 carbon dioxid and acetaldehyde, provided that the acidity of the solution Is 

 kept low." 



Did von Wittich antedate Ostwald in the definition of enzym action? 

 ^y. N. Berg {Biocliem. Bui., 2 (1913), No. 7, pp. Ul-Uo). — A historical discus- 

 sion in regard to priority. 



The precipitation of enzyms from their solutions by moist aluminuni 

 hydroxid, W. H. Welker and J. Marshall {Jour. Amer. Chem. Soc, 35 {1913), 

 No. 6, p. 822). — The enzyms studied were peroxidase (water extract of potato), 

 oxidase (water extract of potato), amylase (saliva), pepsin (water solution 

 of commercial pepsin), pepsin (0.2 per cent hydrochloric acid solution of com- 

 mercial pepsin), rennin (water solution of commercial rennin), trypsin 

 (water solution of commercial trypsin), trypsin (0.5 per cent NasCOs solution of 

 commercial trypsin), trypsin (30 per cent alcohol extract of pancreas), trypsin 

 (30 per cent alcohol extract of pancreas plus an equal volume of 1 per cent 

 NaaCOs solution), amylase (30 per cent alcohol extract of pancreas) and lipase 

 (30 per cent alcohol extract of pancreas). 



All the enzyms, with the exception of amylase, were completely removed from 

 the solution by aluminum hydroxid. "The only zymogen studied was pep- 

 sinogen (prepared by extracting the mucous membrane of the stomach of pigs 

 with 50 per cent glycerol solution), which in 10 per cent and in 25 per cent 

 glycerol solution is removed quantitatively only with the greatest difficulty." 



The precipitation of colloids by means of aluminum hydroxid, J. Marshall 

 and W. H. Welkee (Jour, Amer. Cliem. Soc, 35 {1913), No. 6, pp. 820-822).— 

 " The following solutions were subjected to the treatment with aluminum hy- 

 droxid. In each case the colloidal material was removed absolutely quanti- 

 tatively : Copper, gold, platinum, sulphur, nickel sulphid, cobalt sulphid, cupric 

 hydroxid in NaOH. Prussian blue, Congo red (indicator solution), azolitmin, 

 litmus (neutral), litmus (red), litmus (alkaline), starch paste, soluble starch, 

 erythrodextrin, starch iodid, water emulsion of fat (mechanical entangling of 

 fat globules), soap, emulsion of fat in soap solution (including fat and soap), 

 egg albumin, globulin (edestin in 5 per cent NaCl), gelatin, casein (in one- 

 half saturated lime water) glutenin (in 0.5 per cent Na2C03), nucleoprotein 

 (in 0.5 per cent XasCOs), gliadin (in TO per cent alcohol), ovomucoid, acid 

 metaprotein (in 0.1 per cent HCl), primary proteose, secondary proteose, milk 

 (including fat and protein), and blood serum (protein). 



" The use of aluminum hydroxid, therefore, would appear to be well adapted 

 for preparing oxyhemoglobin from erythrocytes because it removes protein 

 from the blood serum mingled with the dissolved sedimented erythrocytes and 

 also the precipitable protein of these cells themselves, yielding a filtrate from 

 which, as we have found by experiment, oxyhemoglobin more readily crystal- 

 lizes and in a much purer state than by any other known method." 



The direct determination of elementary nitrog-en with the aid of calcium 

 carbid, B. Natus {Ztschr. Anahjt. Chem., 52 {1913), No. 5, pp. 265-292, fig. 1; 

 ahs. in Chem. Ztg., 37 {1913), No. 68, Repert., p. 310).— For the absorption of 

 the nitrogen a mixture consisting of 10 parts of technical carbid and 1 part of 

 calcium chlorid, which was powdered and previously heated to redness, is used. 

 The absorption takes place in a porcelain tube heated to redness, and for dis- 

 placing, hydrogen of known nitrogen content is passed through the tube. The 

 nitrogen is then determined in the carbid mixture by Wilfarth's modification 



