PROXIMATE PRINCIPLES. 
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The first class is divided into three orders. 
1st. Principles which have more oxygen than sufficient to form 
water. 
2d. Principles in which oxygen and hydrogen exist in the exact 
proportion to form water. 
3d. Principles where hydrogen is in excess. 
The 1st order includes vegetable acids: as, 
Acetic acid, or pure vinegar ; this is generally produced by 
fermentation from wine, cider, and some other liquids ; it is also 
found in a pure state in the campeachy wood, and the sap of 
the elm. 
Malic acid may be extracted from green apples and the bar- 
berry. 
Oxalic acid is found in several species of sorrel , belonging 
to the genera Oxalis and Romex. 
Tartaric acid is obtained from the tamarind and the cran- 
berry ; this acid, combined with potash forms what is commonly 
called cream of tartar. 
Citric acid is found in the lemon ; it is mixed with the malic 
acid in the gooseberry, the cherry and the strawberry. 
Quinic acid is obtained from the peruvian bark, (Cinchona.) 
Gallic acid is obtained from the oak, and the sumach ; it is 
highly astringent. 
Benzoic acid is found in the Laurus benzoin , and in the Va- 
nilla ; this is highly aromatic ; it is thought to give the agreea- 
ble odour to balms. 
Prussic acid ; this acid gives out a strong odour like bitter 
almonds ; it is an active poison ; it is obtained from peach meats 
and blossoms, from bitter almonds, &c. 
The 21 order includes gums, sugar, &c. 
The Gums ; of these there are many kinds; they have nei- 
ther taste nor smell ; dissolved in water, they form a mucilage 
more or less thick. The principal gums are, 
Gum. Arabic, which flows from the plant Mimosa nilotica ; 
Common Gums, such as issue from the peachtree, the cherry 
tree, and many others. 
Sugar is a substance which dissolves in water, and has a 
sweet taste ; it is obtained from the sugar cane, the sugar ma- 
ple, from the stalks of indian corn, pumpkins, beets, and sweet 
apples. All vegetables which have a sweet taste may be made 
to yield sugar. 
The 3d orde* includes oils, wax, resins, &c. 
Oils. These are fluid and combustible substances which do 
First class divided into three orders — First order includes vegetable 
acids — Second order, gums and sugar — Third order, oils, &c. — 
