258 § 133. FODDER AND FOOD. 



ly cleaned ; or, if they are very large, select 15-20 from 

 the lot, cut each one in halves from top to bottom, and 

 take a thin slice from the inside of each half. 



If sugar is to be determined for technical purposes, the 

 crown and end of the root should be cut off, in the man- 

 ner practised at the manufactory, before slicing it. 



Weigh quickly the whole number of slices thus ob- 

 tained, to the amount of 500-1000 grms., and dry them 

 on threads in the drying-chamber at a teiiiperature of 

 60-70° C. Pulverize this dried substance coarsely, mix it 

 well together, and weigh the whole quantity, determine 

 hygroscopic water in a portion of 5-6 grms., and keep the 

 rest in well-stoppered bottles. 



1). IVon-Yolatile matter, nitrogen, fat, crude cellulose. 



— ^Determine these as directed under Fodder (§ 129, c, 

 § 130, h, c, d). 



c. Pectose compounds. — These are estimated by the 

 difference between the weight of the dry substance and 

 the sum of the weights of the above-named substances in 

 h, and the sugar. 



d. Sugar* — Boil 2-3 grms. of the powdered substance 

 with several fresh portions of 80-85° 1^ alcohol, as long as 

 anything appears to be taken into solution ; pour each 

 portion of alcohol through a filter that has been dried at 

 100° and weighed, and finally put the whole insoluble 

 substance on the same filter, wash it with hot alcohol, dry 

 it at 100°, and weigh, ignite it, and weigh the ash. The 

 amount of organic matter, burned off by the ignition, 

 can then be estimated ; it consists almost entirely of sugar. 



To determine the sugar more accurately, add considera- 

 ble water to the alcoholic solution, heat the mixture on 

 the water-bath until the alcohol is entirely evaporated, di- 

 lute the residue to about 300 c.c, add 5-6 c.c. of concen- 

 trated sulphuric acid, heat the mixture 3 hours on the 

 water-bath, neutralize the free acid with sodic carbonate, 



