

20 ACIDS, GUMS, RESINS, ETC. 



Principles of Plants. 



The. proximate principles of plants are the products of chemical 

 combinations effected by the action of the vital principle. Such are 

 the vegetable acids, wax, resins, the fixed and volatile oils, etc. The 

 ultimate principles are the elements composing the proximate princi- 

 ples, as carbon, oxygen, and hydrogen, and these are proportionate to 

 the nature and quantity of these elements. Thus those substances 

 composed of them form one class of proximate principles and those, 

 with the addition of nitrogen, another class. Those of the one class 

 have an excess of oxygen, (the general acidifying principle) and there- 

 fore constitute the 



Vegetable acids. Acetic acid, or pure vinegar, is commonly produced 

 by the fermentation of wine, cider, etc, : it is also found pure in the 

 elm. Malic acid may be obtained from green apples, and barberries. 

 Oxalic acid is found in a species of the sorrel, or the genera oxalis and 

 rumex. Tartaric acid is obtained from the tamarind, cranberry, etc.; 

 and when combined with potash, forms cream of tartar. Citric acid 

 is found in the lemon and is mixed with the malic acid as in the goose- 

 berry, cherry and strawberry. Quinic acid is obtained from the 

 Peruvian bark. Gallic acid is from the oak and sumac, and is very 

 astringent. Ben zoic acid is found in the laurus benzoin and vanilla ; 

 it is highly aromatic and is the agreeable odor of balms. Prussic acid, 

 an active poison, is obtained from peach meats and blossoms, bitter 

 almonds, cherry leaves and meats. 



Gums, sugar, etc., compose that order of proximate principles in 

 which hydrogen and oxygen are in the proportion to form water. 

 These unite with water, but have little taste or smell. They com- 

 pose gum arabic ; the common gums of the peach, cherry and other 

 trees. Sugar is from the sugar cane, maple trees, beets, corn stalks, 

 pumpkins, sweet apples and most vegetables with a sweet taste. 



Oils, wax, resins, etc., (in which hydrogen is in excess) are of the 

 second order of proximate principles. They do not unite with water, 

 Oils are fixed, as oil of almonds, olives, flax seed (linseed oil) and 

 volatile, which have aromatic odors that fly off when exposed to the 

 air, as the oils of orange, lavender, rose, jasmine, and peppermint, 

 and when mixed with alcohol they form essences. The aroma is the 

 volatile or ordoriferous part exhaled from aromatic plants, especially 

 abundant in warm climates. Wax is found on the fruit of the bay- 

 berry ; and bees wax is produced by bees from the polen of flowers. 

 Resins exude from the pine, etc. ; they are insoluble in water and in- 

 flammable. Mixed with volatile oils they form balsams which are thick 

 and inflammable, as balsam of tolu, copavia, etc. When mixed with 

 gums they are then gum-resins, as gamboge, guaiacum, aloes, as- 

 safcetida, etc. Gum elastic, or caoutchouc, from South American and 



