20 ANALYSES OF SUGAR BEETS, 1905 TO 1910. 



watch glasses are filled to equal weight and numbered consecutively, 

 as are also the extraction vessels. The procedure is as follows: 



Weigh 26 grams of the beet pulp on a watch glass and transfer to 

 the extraction vessel, then run in 177 cc of dilute basic lead-acetate 

 solution (5 parts of basic lead-acetate solution, Brix 53.5, to 100 

 parts of water), shake and place a stopper which has been covered 

 with tinfoil lightly in the opening. Submerge the whole in a water 

 bath at 75 to 80 C. for 30 minutes, shaking intermittently. When 



all air has been expelled (generally after five 

 minutes), tighten the stopper in the vessel. 

 At the expiration of the time remove and 

 cool. Take out the stopper after shaking 

 thoroughly, filter, and polarize in a 400 mm 

 tube, after addition of a drop of acetic acid to 

 determine the per cent of sugar in the beet. 

 This method does not require very fine 

 pulp and is open to few chances of error. 

 It, together with the Sachs Le Docte method, 

 has a decided advantage over the other hot 

 digestion method, in that there is little chance 

 of a loss of sample by the container breaking. 

 When working with glass flasks one is likely 

 to ruin many determinations. For quick 



FIG. 5.-Her Z feld's metallic beaker. WQrk an( j when mftny samples are to be run, 



large heating and cooling vessels can be used and the dishes taken 

 from the one and placed immediately in the other to cool, without 

 risk of losing the determination, thereby saving considerable time. 

 This method has been adopted by the Society of the German Sugar 

 Industry, and with a few modifications in apparatus, but not of 

 procedure, by a number of other sugar associations of Europe. 



ALCOHOL METHODS. 



The methods using alcohol as the solvent may be divided into two 

 classes digestion and extraction methods. The former is again 

 divided into hot and cold digestion methods. 



COLD ALCOHOL DIGESTION METHOD. 



Weigh 52 grams of the beet cuttings and transfer to a flask (having 

 a capacity of 201.2 cc) with 90 per cent alcohol, add 4 cc of lead 

 subacetate solution and shake, then add more 90 per cent alcohol 

 with shaking to remove the air bubbles, complete the volume, allow 

 to stand half an hour, and add alcohol if a decrease in volume is 

 noted. Thoroughly shake the flask and filter, keeping the filter 

 covered to prevent loss by evaporation. Polarize in a 200 mm tube. 



