HYDROCHLORIC ACID 335 



made by mixing six fluid ounces of the stronger acid with 

 water until the mixture at 60 Fahr. measures twenty fluid 

 ounces. It has the specific gravity 1*052, and contains 10' 58 

 per cent, of hydrogen chloride. The test for hydrochloric 

 acid is silver nitrate, with which it produces a curdy white 

 precipitate, insoluble in nitric acid, but soluble in excess of 

 ammonia. Its chief impurities are sulphuric and sulphurous 

 acids, nitrous compounds, chlorine, iron, and occasionally 

 traces of arsenic. 



ACTIONS AND USES. Concentrated doses are corrosive and 

 irritant ; medicinal doses are astringent, antiseptic, and 

 tonic. Topically it is used as a caustic, stimulant, astringent 

 and antiseptic. 



Toxic EFFECTS. Concentrated solutions have a strong 

 affinity for the water, bases and albuminoids of the tissues. 

 They leave upon them a white film. When swallowed they 

 cause gastro-enteritis. Independently of irritant or cor- 

 rosive effects, they appear to destroy life by neutralising 

 the alkali of the blood. Rabbits and herbivora are stated to 

 suffer in this way more readily than dogs or other carnivora. 

 Seven or eight grammes per kilogramme of body- weight may 

 be given to rabbits in twenty-four hours without serious 

 results, but nine grammes prove fatal in a few hours, causing 

 frequent laboured breathing, quick pulse, imperfect power 

 of moving, and death, depending upon fatal diminution of 

 the alkali in the blood, determining first stimulation, and 

 soon paresis of the respiratory centre. That these toxic 

 effects directly depend upon neutralisation of the alkali in 

 the blood appears to be demonstrated by experiments, in 

 which animals nearly dying from acid poisoning promptly 

 revived when sodium carbonate was injected into the veins. 

 The alkaline antidote proves effectual even when three times 

 the ascertained fatal dose of acid has been administered 

 (Phillips). 



MEDICINAL USES. Hydrochloric acid, made into an 

 electuary with glycerin, treacle, or honey, or diluted with 

 water (2 to 5 per 1000), exerts astringent and antiseptic 

 effects on irritable, relaxed, or ulcerated condition of the 

 mouth and throat. Stimulating the mucous membrane of 

 the mouth, it reflexly evokes secretion of saliva, moistening 



