ii8 THE CARBOHYDRATES 



a byicf treatment with hot dikite hydrochloric acid. These 

 reserve celluloses contain mannanes and galactanes. 



Mannane serves in the same way as starch as a reserve food- 

 supply to a very large number of different plants. It may be 

 regarded as an anhydride of mannose, since it yields this 

 substance on hydrolysis ; it occurs either alone or united to 

 anhydrides of other sugars, such as glucose, galactose, pentose, 

 etc., in a great many different forms. 



A fairly pure specimen of mannane can be obtained from 

 yeast by a somewhat elaborate method devised by Hessenland.* 

 It is a white amorphous substance, which is somewhat soluble 

 in water and swells up in dissolving; it is insoluble in alcohol 

 but readily soluble in alkali, and is strongly dextro-rotatory, 

 a^ = -h 2837-287-6.° 



Mannane occurs in salep mucilage, and has been extracted 

 by Ritthausen f and Effront + and others from wheat and 

 barley. Mannanes are also found in Penicillium glaiicum, 

 ergot, in the roots of several plants such as asparagus, chicory, 

 Helianthus and Taraxacum ; also in the wood and leaves of 

 many trees, such as lime, chestnut, apple, mulberry, certain 

 Oleaceae and conifers ; the so-called reserve celluloses and 

 hemi-celluloses contained in seeds of Palmaceai, Liliaceae, 

 elder, cedar and larch, and many other plants, are also very 

 rich in mannanes. 



PARAMANNANE. 

 Paramannane is a variety of mannane which is characterized 

 by being much more resistant to hydrolysis ; this substance, 

 which is contained in coffee beans, is only slightly acted on by 

 hot dilute mineral acids, potassium chlorate and hydrochloric 

 acid, but dissolves in a concentrated hydrochloric acid solution 

 of zinc chloride. It is accordingly frequently classed as a 

 mannose-cellulose. 



CAKUBIN OR SECALANE. 



Carubin^ is the name giyen to a substance occurring in 

 the seeds of Ceratonia siliqua, and in various cereals such as rye 



* Hessenland : " Z. d. Vereins d. Deut. Zuckerind.," 1892, 42, 671. 

 t Ritthausen: "J. prakt. Chem.," 1867, I02, 321, and " Chem. Zeit.," 1897, 

 21, 717. 



i Effront: " Compt. rend.," 1897, 12$, 38, 116. 

 %lbid., 124, 200, and 12$, 116 and 309. 



