GUMS AND MUCILAGES. 3I 



of substances, rather than as a single body of definite 

 chemical composition. 



Bassortn, like cerasin, is probably best described by 

 referring to "the bassorins." They are colorless bodies, 

 • very slightly soluble in water. They contain few or no 

 organic compounds. 



Neither cerasin nor bassorin reduce Fehling's solution, 

 and they both yield arabinose and galactose by hydro- 

 lysis. Both bodies are closely related to the plant 

 mucilages and pectin bodies. 



The method of the origin of gums in plants has been 

 the subject of much diversity in opinion. While formerly 

 they were held to be secretions, they are now regarded, 

 for the most part, as chemical modifications of the tissues. 

 Traces of tissue structure sometimes persist in slight 

 degree in some — tragacanth, for example. All or any 

 of the tissues, normal or pathological, may be affected 

 by this metamorphosis of the cell walls. In all proba- 

 bility the metamorphosis is brought about by the action 

 of the ferments, and Wiesner* in 1885 isolated a diastatic 

 ferment which he thought caused the formation of gums. 



Gums occur as the commonest plant products. While 

 any tissue may be converted into gum, those of the organs 

 of the periphery are more liable to undergo the metamor- 

 phosis. 



In general the various commercial gums may be 

 classed, following Wiesner, as follows, the words arabin, 

 cerasin, and bassorin being taken in the broad sense 

 already outlined. 



(i) Arabin gums: Those rich in the arabins. Cerasin 

 and bassorin are not present, or in very slight quantities. 

 Here belong the bitter varieties of Acacia, Feronia and 

 Anacardium gums. 



(2) Cerasin gums: Those rich in cerasin and containing 

 arabin as well. The gums of the Prunus type are here 



* Sitztingb. d. k. Akad. der Wiss. in Wien, 1885. 



