376 VEGETABLE DRUGS 



Tinctura Benzoini. Tincture of Benzoin. (U. S. P.) 



Made by maceration of benzoin, 200, in alcohol; filtration, and addition of 

 alcohol to make 1000. 



Dose.—H. & C, 51, (30); D., 3ss-i, (2-4.). 

 Tinctura Benzoini Composita. Compound Tincture of Benzoin. (U. S. & B. P.) 



Synonym. — Friar's balsam. 



Benzoin, 100; purified aloes, 20; storax, 80; balsam of tolu, 40; alcohol to 

 make 1000. Made by maceration in alcohol and filtration. (U. S. P.) 



AciDtjM Benzoicum. Benzoic Acid. CjHoOj. (U. S. & B. P.) 



Synonym. — Acide benzoique, fleurs de benjoin, Fr.; benzoesilure, benzoeblu- 

 men, G. 



Derivation. — Obtained from benzoin by sublimation, or artificially prepared. 



Properties. — In lustrous scales or friable needles. The synthetic acid is 

 white, odorless, or with a slight odor of benzaldehyde ; the natural acid is white, 

 or yellowish, acquires a darker color on exposure to light, and has a slight odor 

 of benzoin. Benzoic acid has a pungent taste, is somewhat volatile at moderately 

 warm temperatures and freely volatile with steam. Soluble in 275 parts of water, 

 and in 2.3 parts of alcohol. Also soluble in 3 parts of ether. 4.5 parts of chloro- 

 form, and readily soluble in carbon disulphide, benzene, fixed and volatile oils, 

 but sparingly soluble in petroleum benzin. 



Incompatibles. — Alkalies, ammonium carbonate. 



Dose.—n. & C, 3ii-iv, (8-15) ; D., gr.v-xv, (.3-1). 



Ammonii Benzoas. Ammonium Benzoate. NH.CvHjOj. (U. S. & B. P.) 



Made by the action of benzoic acid and ammonia water. In white crystals 

 or crystalline powder. Soluble in 10 parts of water; in 35.5 parts of alcohol. 



Dose. — Same as benzoic acid. 



SoDii Beszoas. Sodium Benzoate. NaCiHjOj. (U. S. & B. P.) 



Made by the action of a hot solution of sodium carbonate on benzoic acid. 

 Occurs in a white amorphous or crystalline powder. Soluble in 1.8 parts of 

 water; in 61 parts of alcohol. 



Dose. — Same as benzoic acid. 



Action of Benzoin, Benzoic Acid and Benzoates. 



These substances may be represented by benzoic acid. 



Action External. — Benzoic acid is an irritant applied externally, also 

 when its vapor is inhaled. It is an efficient antiseptic; a solution 

 (1-1000) will inhibit the growth of many forms of bacteria. 



Action Internal. — Medicinal doses of benzoic acid exert only an anti- 

 septic action in the alimentary canal. Large doses occasion increased 

 bronchial and cutaneous secretion, with accelerated pulse. Enormous 

 doses cause gastro-intestinal irritation, slowing of the pulse and respira- 

 tion, convulsions, general paralysis and asphyxia. Benzoic acid is ab- 

 sorbed into the blood, acts as an antipyretic in fever, and is converted 

 (probably in the kidneys) into hippuric acid and eliminated in the urine 

 as such. It thus renders an alkaline urine acid, and stimulates and exer- 

 cises an antiseptic influence upon the urinary mucous membrane. The 

 change into hippuric acid is due to combination with a nitrogenous body — 

 glycocoll — but the source of glycocoll is uncertain. 



Benzoic acid C^HgOj-j-glycocoll C2H5N02=liippuric acid CgHgNO, 

 +H,0. 



Benzoic acid is somewhat diuretic, but does not alter the composition of 

 the urine in any constant manner, although metabolism is said to be in- 

 creased. It is eliminated by the bronchial mucous membrane, augmenting 

 secretion, and acting as an antiseptic in the bronchial tubes. When the 



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