XI. METHODS FOR THE ANALYSIS OF SUGARHOUSE PRODUCTS. 



PROVISIONAL. 



1. Sucrose, 

 (a) SCHEIBLER'S ALCOHOLIC METHOD. 



In the direct analysis of the beet with the Soxhlet-Sickel apparatus by Scheib- 

 ler's method, proceed as follows for the extraction of the sucrose : 



Place a plug of absorbent cotton in the bottom of the tube, then introduce 

 26.048 grams (Mohr cc) of the pulped beet, or 32.58 grams (twice the normal 

 weight), according to the polariscope in use, pressing the pulp lightly with a 

 rod. Very small fragments of the beet may be used instead of pulp. Connect 

 the extractor with the reflux condenser. Place 75 cc of 95 per cent alcohol in 

 the flask and connect with the extractor; heat the flask in the water bath and 

 continue the extraction from half an hour to two hours or more, according to the 

 state of division of the sample. Use somewhat weaker alcohol if only 16.29 

 grams of pulp be taken. Cool and remove the flask, substitute a second con- 

 taining 75 cc of 75 to 80 per cent alcohol, and continue the extraction to ascer- 

 tain whether the first extraction were complete. 



Fill the first flask to the 100 cc mark, after treating the sample with two 

 or three drops of lead subacetate. Mix the contents of the flask, filter, and 

 polarize. Having extracted the normal weight of pulp, the polariscopic reading 

 is the per cent of sucrose in the sample. The extract in the second flask should 

 also be polarized as a check upon the extraction. 



Great care is essential in the polarization of alcoholic solutions. The small- 

 est quantity of lead subacetate that will clarify the solution should be used. 

 The solution must be protected from evaporation during the filtration by a 

 cover glass. Avoid irregularities in the temperature of the solution in the 

 observation tube due to the warmth of the hands, since the density of the solu- 

 tion in different parts of the tube will vary under such conditions; striae will 

 form, rendering an accurate reading impossible. The Soxhlet extraction appa- 

 ratus is much more effective than Scheibler's original Instrument. 



(b) PELLET'S AQUEOUS METHOD (HOT DIGESTION). 



Any good rasp may be used in the preparation of the pulp for this method. 

 Special flasks with enlarged necks are convenient. Transfer 26.048 grams 

 (Mohr cc) of the pulp to the flask, using a little water to wash the weighing 

 capsule and funnel. The flasks are graduated to contain 200.6 cc for the 

 Schmidt and Haensch, or any instrument using the above normal weight, in 



87404 Bull. 10709 7 75 



