252 § 130. FODDER a:sj) food. 



110° C, and calculate the amount of dry substance in the 

 powder. 



b. Protein Compounds. — ^Ignite 0.7 to 1 grm. with 

 soda-lime (§ 85). 



c. Fatty Substances. — Extract these from 6-8 grras., 

 by ether (§ 87). 



d. Crude Cellulose.— Boil a quantity of the powder 

 containing about 3 grms. of dry substance, half an hour, 

 with 200 c.c. of dilute sulphuric acid, containing 1.25° \^ 

 of monohydrated acid, in a flask that is attached to the 

 lower end of a Liebig's condenser; let the mixture stand 

 till the solid particles settle to the bottom ; draw the clear 

 liquid off into a beaker, as completely as possible, with a 

 small siphon, and finally with a pipette ; pour 200 c.c. 

 of water over the residue in the flask, boil again half an 

 hour in the same manner as before, and as before let the 

 solid particles settle and remove the clear liquid ; repeat 

 this operation once more. 



Then boil the substance in the same way with 150 c.c. 

 of water and 50 c.c. of a solution containing 50 grms. of 

 fused caustic potash in the litre, and afterwards twice with 

 200 c.c. of water, removing the liquid each time in the 

 same manner as described for the sulphuric acid, but put- 

 ting these alkaline washings in a beaker b}^ themselves ; 

 finally, bring the residue on a dried and weighed filter. 

 Then, with the siphon, draw off the clear alkaline liquid 

 from any sediment that may have been deposited in it ; 

 transfer this sediment to the same filter, and wash the 

 whole, as long as the washings have an alkaline reaction ; 

 then add the sediment in the beaker containing the acid 

 washings, after drawing off the clear liquid with the 

 siphon, and wash again, as long as the Avashings have an 

 acid reaction. Wash the contents of the filter succes- 

 sively with alcohol and ether ; dry the filter and its con- 

 tents at 110°, weigh, incinerate the residue, and weigh 



