138 THE CARBOHYDRATES 



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 Palmaceae, 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. 



CARUBIN OR SECALANE. 



Carubin * is the name given to a substance occurring in 

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

 and barley. In its characters it closely resembles mannane, 

 and by some authors is regarded as identical with it ; when 

 dry, it is a spongy friable substance which swells upon the 

 addition of water. It is soluble in cold water and is optically 

 inactive. Its sugar is fermentable and non-crystalline. 



GA^ACTOSANES. 



GALACTANE. 



Exactly analogous to the mannanes are the galactanes, 

 which may be looked upon as anhydrides of galactose. They 

 occur in a great variety of different forms, some of which are 

 readily hydrolysed by warming with alkali, while others are 

 very resistant even towards boiling alkali. Four galactanes 

 have been described, which are distinguished by the prefixes 

 a-, /3-, 7- and 8- ; they are all amorphous substances 

 which dissolve with difficulty in water, and on hydrolysis yield 

 galactose. 



* Effront: " Conipt. rend.," 1897, 124, 200, and 125, 116 and 309. 



