§ 131. FODDER. 253 



the ash. The difference between the total weight of the 

 insoluble residue and that of the ash equals the crude 

 cellulose or fibre. 



The residue obtained in this way is a mixture of cellu- 

 lose with various other substances. When obtained from 

 the grasses it is comparatively the purest, but contains 

 2-3" I g of i^rotein compounds. When prepared from clover, 

 it contains 5-6° 1^ of the same substances ; but even after 

 subtraction of these albuminoids, the residue contains 

 1-7° lo more carbon than pure cellulose. 



131. a. Dry Matter SoluWe in Water.— To determine 

 the amount of substance soluble in w^ater, boil 10-20 

 grms. with 10-12 successive portions of 200-300 c.c. of 

 water in a flask that is connected with the lower end of a 

 Liebig's condenser (§ 39, o), and after each boiling, sepa- 

 rate the water as quickly as possible from the residue ; all 

 the portions of w^ater are afterwards passed through a 

 ribbed filter, that is pierced with the glass rod and 

 replaced by a new one as often as it becomes choked up, 

 so that the filtration shall proceed as rapidly as possible. 

 Bunsen's method of filtration can be used in this case to 

 great advantage. 



The extraction should, at any rate, be finished in one 

 day, so that the solution may not begin to mould before 

 it is examined. 



Evaporate 200 c.c. of the extract almost to dryness, in 

 a platinum dish, on the water-bath ; complete the desic- 

 cation on hot sand, under the receiver of the air-pump 

 (§ 90), and weigh the residue. 



h. Non- volatile Matter Solnble in Water.— Incinerate 

 the residue obtained in a. Generally an ash free from 

 coal can be obtained ; if not, filter out and weigh the 

 coal in the usual manner, and subtract it and the carbonic 

 acid from the total residue. 



An excess of mineral matters is always found in this 



