338 DILUTED NITRO-HYDROCHLORIC ACID 



removed by the knife ; for dissolving the hardened scurf, 

 and promoting a healthier condition of skin in mallenders 

 and chronic eczema ; and as a caustic in poisoned wounds, 

 necrosis, canker, and foot-rot. As an escharotic it is gener- 

 ally applied on a glass rod ; surrounding tissues are protected 

 by lard or oil, and undue action arrested by subsequent 

 washing with an alkaline solution. Freely diluted in hot 

 water, it abates the itching of nettlerash. Dissolved in 

 two or three hundred parts of water, it is used for sponging 

 the skin, and for relieving the tenderness and tension of piles 

 in dogs. Nitric acid preserves putrescible substances, and 

 prevents evolution of hydrogen sulphide more effectually 

 than either hydrochloric or sulphuric acid ; but as a dis- 

 infectant, it cannot be recommended, owing to its action on 

 organic and metallic substances, and the irritant effects of 

 its fumes. 



DOSES, etc. Of the diluted medicinal acid, horses or 

 cattle take f3i- to f3ij. ; sheep and pigs, H\x. to 3J- ; dogs, 

 fl\ij. to U\xx. It must be largely diluted with water or other 

 bland fluid, and is often conjoined with bitters. For ex- 

 ternal application, a drachm of strong acid in a pint of water 

 suffices for all except escharotic purposes. An ointment is 

 occasionally used, made by melting together in a glass vessel 

 a pound of olive oil, four ounces of lard, and when the 

 mixture is nearly concrete, adding six drachms of nitric 

 acid, and stirring briskly with a glass rod till the whole 

 solidifies. A paste made with sulphur and lard is used for 

 extirpating warts, and stimulating patches of scurfy skin. 



DILUTED NITBO-HYDBOCHLORIC ACID 



ACIDUM NITRO-HYDROCHLORICUM DILUTUM. Nitro- 

 Muriatic Acid. Aqua regia. An aqueous solution of 

 free chlorine, hydrochloric, nitric and nitrous acids. 



The diluted nitro-hydroehlorie acid of the B.P. is prepared 

 by adding to twenty-five fluid ounces of distilled water in 

 a glass-stoppered bottle three fluid ounces of nitric acid and 

 four of hydrochloric, and allowing the mixture to stand 

 for fourteen days before it is used. It contains free chlorine, 

 and has the specific gravity T07. 



