410 EXPERIMENT STATION RECORD. [Vol.40 



alkalimetric titration. Heavy metals or calcium must first be precipitated 

 by an excess of sodium carbonate and filtered off and the solution made exactly 

 neutral, using methyl orange as an indicator. 



While the method is claimed to give only approximate results, the errors are 

 mainly compensatory, due to the presence of small amounts of both Ba and 

 SO* ions. 



Determination of hypochlorites and chlorates in the same solution, I. M. 

 Kolthoff (Pharm. WeekbL, 55 (1918), Xo. 37, pp. 1289-1295) .—The hypo- 

 chlorites were determined as follows : 



To 25 cc. of N/10 As 2 0» solution are added ."> cc. of 4 N acetic acid and 3 drops 

 of a 2 per cent solution of methyl red. The hypochlorite solution to be tested 

 is run in from a burette until the solution is decolorized. The volume of hypo- 

 chlorite required contains 8S.75 mg. of active chlorin. 



The chlorates are determined by adding to the clear solution obtained above 

 25 cc. of 0.1N As.Oj and 20 cc. of concentrated hydrochloric acid, heating for 5 

 minutes, and titrating the excess <>f a^ : <>i with N/10 potassium bromate, using 

 indigo as an indicator. One cc. of As : < > 3 consumed is equivalent to 1.4 mg. of 

 C10» or represents a loss of 3.45 mg. of available chlorin. 



The method is said to be applicable to the determination of the strength of 

 chlorin water. 



A convenient and efficient digestion apparatus for the determination of 

 crude fiber, II. I>. Speabs [Jour. Indus, nmi Engin. Chem., 11 (1919\. No. 2. pp. 

 140, llfl, ftp*. 8). — In the apparatus described, which is said to have been used 

 satisfactorily for several years in the feeding stuffs laboratory of the Kentucky 

 Experiment. Station, the rellux condensers employed in the official method for 

 the determination of crude fiber are substituted by a series of round flasks with 

 intake and outflow tubes, connected by rubber tubing through which (lows the 

 water for cooling. The llasks are about 2J in. in diameter, so as to res! prop- 

 erly in the mouth of beakers 2A In. In diameter, 6 in. In height, and of about 

 375 cc. capacity, which are used as the digestion containers. The flasks are sus- 

 pended over the beakers by loops of sheet iron or zinc. 



While there may be a slight loss of water from evaporation during the boiling 

 on account of the condensers not being attached to the digestion containers by a 

 tight joint, it is believed that the concentration of the solvents thus brought 

 about is not enougb to cause an appreciable error, as is shown by a table of 

 duplicate determinations made with the apparatus. 



The detection of vegetable gums in food products. A. A. < 'ook and A. C 

 Woodman {-lour. Indux. and l-'.nriin. Chrm.. 10 (1918), ,Vo. 7. pp. 530-53-1: ahs. in 

 Jour. 80C. Chrm. Indus., 37 [IMS), No. 17. p. ,527.4 ) .—The procedure consists, in 

 brief, in removing the protein of the food mixture by heating with acetic acid 

 and tannin, and then precipitating the gums from the filtrate by acetone. The 

 precipitate is dissolved in acetic acid, and ammonia is added to remove the 

 soluble phosphates. The pure gum is then precipitated by alcohol. 



The possible maximum vitamin content of some Philippine vegetables, 

 H. C. Bbiix and C. Amncastrf. ( Philippine -four, fifed., Sec*. 1, 12 t (927), No. 3. 

 pp. 127-182). — A method based npon the property of pyridin derivatives of 

 yielding approximately three-fourths of their nitrogen by the Kjeldahl method 

 has been employed for deterndning the relative amounts of vitamins in various 

 Philippine vegetables. 



A portion of the fresh vegetable was dried at a low temperature, and 1(10 gm. 

 of the finely ground material was thoroughly extracted with methyl alcohol. 

 The alcohol was evaporated at a low temperature and the residue taken up in 

 water and filtered. After acidifying the filtrate with sufficient sulphuric acid 



