OLEUM OLIVM. 283 



3. SPECIFIC ACTION AND USES. 



Benzoic acid and its salts act upon nutrition very much 

 like the salicylates, as far as they have been investigated ; that 

 is, they are antipyretic, whilst they are said to increase meta- 

 bolism. They have been used to lower the temperature in 

 pyaemia, acute rheumatism, and specific fevers ; but their effects 

 are very uncertain, and frequently very unpleasant. Their 

 internal use in phthisis has quite failed, and in diphtheria they 

 are of doubtful value. 



4. KEMOTE LOCAL ACTION AND USES. 



Benzoic acid is excreted by the kidneys, partly unchanged, 

 partly as hippuric acid, and occasionally as succinic acid, 

 increasing the flow of urine ; by the skin and salivary glands, 

 unchanged, stimulating their secretions ; and probably by the 

 respiratory organs, decidedly increasing the amount of ex- 

 pectoration. These remote local effects are turned to useful 

 account. The acid and its ammonia salt are extremely valuable 

 in inflammation of the bladder with alkalinity of the secretion 

 and phosphatic deposits, by acidulating the urine and stimu- 

 lating and disinfecting the mucous surfaces ; and they are 

 used all the more that they are almost the only certain means 

 of neutralising morbid alkalinity of the urine which we possess. 

 As an expectorant, benzoic acid, chiefly as the compound 

 tincture, or contained in Tinctura Camphorae Composita, 

 Tinctura Opii Ammoniata, and the balsams of Tolu and Peru, 

 is very useful in chronic bronchitis, when the bronchial pro- 

 ducts are abundant, thick, possibly foul, the mucous membrane 

 chronically inflamed and weak, and reflex activity low. 



PLEACE^. 



Olivae Oletim OLIVE OIL. The oil expressed in 

 the south of Europe from the ripe fruit of Olea europsea. 



Characters. Pale yellow, with scarcely any odour, and a 

 bland oleaginous taste ; congeals partially at about 36. 



Composition. Olive oil consists of 72 per cent, of a fluid oil, 

 olein, and 28 per cent, of a solid oil or stearoptene, palmitin. 

 These are compounds of a base, glyceryl (CgHg), with oleic acid 

 (C l9 H;j40 2 ), and. palmitic acid (Q^H^C^) respectively. 

 Dose, % to 1 fl.oz. 



Preparations. 



Many Plasters, Liniments, Ointments, Enema Magnesias Sul- 

 phatis, Charta Epispastica, and Cataplasma Lini. It is 

 also the source of the Soaps and Glycerine. 



