640 BOTANY AND PHARMACOGNOSY. 



VII. EXUDATIONS, JUICES AND OTHER PLANT PRODUCTS. 



A large number of substances are used in medicine which 

 represent to a greater or less extent the constituents of the cells 

 or alteration or decomposition products of them. These include 

 exudations, inspissated juices, extracts, products of distillation, 

 etc. The exudation products of milk-vessels or secretion reser- 

 voirs are eliminated either through natural or artificial wounds 

 of the stem, and they are collected in special receptacles, as in the 

 case of gamboge, scammony and turpentine ; or they are allowed 

 to dry and more or less harden on the stem, afterward being col- 

 lected, as acacia and tragacanth ; or the more or less plastic or 

 partially dried exudation may be made into masses, as those of 

 lactucarium and opium. These products may be grouped accord- 

 ing to their origin, some of them being derived from the Coniferae : 



I. Natural Exudations. 



Carbohydrates ...[ Gummy exudations {; ' ^ ^'^ ;;_' ; ; ;;;_';;'^,'_'; ^ ^ , Tragacantha 



Saccharine exudation Manna 



Balsam Styrax 



Balsamic resin Benzoin 



Resinous products 



Oleo-resins / . ; Terebinthina 



( lerebmthina canadensis 



Asafetida 



Gum-resins Cambogia 



Myrrha 



. Scammonium 



Guaiacum 



'- Resins J Mastiche 



I Fix burgundica 



Elastica 



Milk-juices J Lactucarium 



(^ Opium 



2. An Excrescence. 

 Formed as a result of the puncture of an insect Galla 



3. Artificially Prepared Products. 



Carbohydrates Starch grains Amylum 



TvT u u J . ( Extract Gambir or Catechu 



JNon-carbohydrates J . , 



(inspissated juices. . / -r-- 



Product of destructive distillation Fix Liquida 



Residue from the distillation of turpentine Colophony 



