acids. 34 1 



less, transparent fluid, extremely corrosive, and emitting, when 

 exposed to the air, white fumes. It acts powerfully on animal and 

 vegetable substances ; when applied to the skin, it tinges the 

 cuticle yellow, and causes it soon to peel oft'; when poured on the 

 volatile oils, it immediately sets them on fire ; when digested in 

 sugar, it converts it into oxalic acid : it is capable of oxidizing all 

 the metals, and combines with the earths, alkalies, and metallic 

 oxides, forming a peculiar class of salts, which have been called 

 nitrates. The nitric acid, as it occurs in commerce, is well 

 known under the name of aqua forth ; it is of a deep orange- 

 colour, and is generally contaminated with the sulphuric and muri- 

 atic acids. For the purposes of medicine, nitric acid is kept in a 

 diluted form [Acid Nitricum dilutinn, Ph.) in order to admit of 

 its dose being easily regulated. In this state it may be given in 

 doses of from 10 to 40 drops, in a glass-ful of water, compound 

 infusion of roses, or in any of the bitter vegetable infusions, 

 especially those of cinchona or of gentian. Its effects are those of 

 a refrigerant, tonic, and antiseptic. It has been advantageously 

 administered in some dyspeptic affections, with a view of relieving 

 violent sickness and anorexia, in chronic hepatitis, in obstinate 

 cutaneous eruptions, in low typhoid fevers, and as an adjunct to 

 mercury in the cure of syphilis. Speaking of its use in the treat- 

 ment of the venereal disease, Mr. Brande justly observes, "although 

 in such cases it may be occasionally efficacious as a tonic, it is by 

 no means to be regarded as possessing any direct influence over 

 the disease corresponding with that of mercury. In some cases 

 of eruptions, and in ulcerations of the legs, an alterative course of 

 medicine, consisting of nitric acid and small doses of mercury, has 

 been found of service." Externally, nitric acid is sometimes used 

 for destroying warts and other cutaneous excrescences; it has also 

 been strongly commended by some writers, as an escharotic, in 

 cases of hospital gangrene. Two or three drachms of the diluted 

 acid added to one pint or more of water, forms an excellent appli- 

 cation to certain ill-conditioned sores and ulcers. 



Sp. 5. Boracic Acid, or Sassolin. — This acid occurs in 

 scaly crusts. Its taste is harsh and sub-acid. Its colours arc 

 white, or yellowish-white. It is found on the borders of hot 



