214 Cellulose 



Nothing, however, has as yet been established in regard to the 

 constitution of these products. 



They are no doubt in the main derived from the non- 

 cellulose or lignone complex, but the author's numbers do not 

 warrant his view that the attack of the alkali is confined to this 

 complex ; it is evident that the cellulose is considerably attacked 

 also, and the method cannot be recommended as a process for 

 cellulose estimation. For the original papers see Zeitschr. PhysioL 

 Chem. 14, pp. 15, 217. 



(2) Chromic add in presence, of sulphuric actd (cone.) de- 

 termines complete conversion of the carbon of the woods 

 into the gaseous oxides CO 2 and CO ; the proportion of 

 the latter is small. The reaction is available, therefore, as 

 a combustion method, under the conditions previously de- 

 scribed. 



Pectocelluloses and Mucocelluloses. The second 

 great division of the compound celluloses are those of which 

 the non-cellulose constituents are related to the * pectic ' group 

 of compounds. Hugo Muller (Pflanzenfaser), in stating the 

 results of proximate analyses of raw fibrous materials, completes 

 the list of constituents with an undetermined aggregate de- 

 scribed as ' Incrusting and intercellular substance and pectic 

 constituents, calculated from loss ' i.e. having determined ash, 

 water, water extract, fat and wax, and cellulose, the residue is 

 estimated by calculation, and stated under the above aggregate 

 description. The question of ' incrustation ' is rather morpho- 

 logical than chemical. In the lignocelluloses we have ample 

 evidence that the process of lignification is an intrinsic trans- 

 formation of tissue-substance. It is, of course, consistent with 

 this view that there should be a concurrent process of deposi- 

 tion of substance external to the cells themselves, destined for 



