Pectocelluloses and Mucocelluloses 225 



after previously purifying the raw material by digesting with 

 dilute alkaline solutions in the cold. According to Honig and 

 Schubert (Wien. Akad. Ber. 96, [2] 685), lichenin is accom- 

 panied in the plant by an amorphous form of starch. 



On hydrolysis lichenin yields crystallisable dextrose, and 

 on oxidation with nitric acid, saccharic acid. With glacial acetic 

 acid it yields an amorphous triacetate, C 6 H 7 O 2 (C 2 H 3 O2),v 



CARRAGHEEN MUCILAGE is obtained from the seaweed 

 Fucus crispus (C. Schmidt, Annalen, 51, 56) on boiling with 

 water. This raw material is characterised by the presence of 

 galactose groups, yielding 22 p.ct. mucic acid on oxidation with 

 nitric acid, and also crystallisable galactose on hydrolysis with 

 boiling dilute acids. 



This concludes our brief notice of the pectocellulose group. 

 It appears that there are two well-marked sub-groups of these 

 products : (i) the pectocelluloses proper, occurring in structures 

 of a more permanent character fibrous and parenchymatous 

 tissues of the stems and roots of Phanerogams ; (2) pecto- 

 celluloses occurring chiefly in seeds and fruits of Phanerogams 

 and the tissues of Algae ; distinguished from the former by yield- 

 ing to the action of water, giving the peculiar solutions known as 

 mucilages. Hence the proposed name mucocelluloses for the 

 parent tissue-substance having these properties. 



These groups are further distinguished by the characteristics 

 of their hydrolysable constituents, the former yielding com- 

 plexes in which acid features predominate ; the latter yield 

 neutral solutions, and in fact, on ultimate hydrolysis, various 

 hexoses and pentoses. 



Adipocelluloses and Cutocelluloses. Cork and 

 Cuticularised Tissues. The plant represents, in the one 

 view, an assemblage of synthetical operations carried on 

 within a space enclosed and protected from the destructive 



Q 



