ACACIA. , 237 



hepatic and cardiac dropsy, but must be avoided in the dropsy 

 attending Blight's disease. It is much to be preferred to 

 the oleo-resin for this purpose. The latter is chiefly employed 

 in inflammatory affections of the bladder and urethra, especially 

 gonorrhoea, when the first acute symptoms have somewhat 

 subsided. It is best combined with potash and cubebs. Natu- 

 rally it is less useful in the vaginal gonorrhoea of women. 

 Copaiba is now seldom used in bronchial affections, on account 

 of the unpleasant effects attending it ; but in hospital practice 

 it will sometimes diminish and disinfect the profuse foul pro- 

 ducts of chronic bronchitis and bronchiectasis when other 

 means have failed. It is occasionally given in skin diseases. 



Acaciae GiiMimi GUM ACACIA. A gummy 

 exudation from the stems of one or more undeter- 

 mined species of Acacia. 



Characters and Tests. In spheroidal tears, nearly colour- 

 less, and opaque from numerous minute cracks ; or in fragments 

 with shining surfaces ; brittle ; bland and mucilaginous in 

 taste ; insoluble in alcohol, but soluble in water. 



Impurities. Starch; detected by the iodine test. Gum 

 resins ; detected by smell and taste. 



Incompatibles. Alcohol and sulphuric acid, borax, pe^rsalts 

 of iron, and subacetate of lead. 



Composition. Gum arabic consists chiefly of arabic acid 

 or arabin, C 3 ,.H 66 33 , combined with calcium, magnesia, and 

 potash, and 17 per cent, of water. 



Preparations. 



Mucilago AcacisB. Gum, 40 ; Water, 60. Dose, 1 to 4 fl.dr. 

 Gum Acacia is also contained in Mistura Cretaa, Mistura 

 Guaiaci, Pulvis Amygdalae Compositus, Pulvis 

 Tragacanthae Compositus, and in all Trochisci. 



ACTION AND USES. 



Acacia possesses very similar properties and physiological 

 effects to those of tragacanth, and is employed for the same 

 purposes. (See Tragacantha.} An objection to its pharmaceutical 

 use is its liability to undergo fermentation, and cause indiges- 

 tion, flatulence, and diarrhoea. Its principal application thera- 

 peutically is for cough in the form of lozenges and linctuses. 



