Nitric Acid

(Chem.) A compound which, in ordinary circumstances, cannot exist except in combination at least with water: the nitric acid of the shops, termed aqua fortis, is united with more or le of that fluid. It is colorle , unle it contains nitrous acid; exposed to the light, it gradually becomes of a yellow or reddish tint, according to the quantity of nitrous acid formed by decomposition of the nitric acid. It is intensely corrosive, produces painful sores if brought in contact with the animal body; and, though removed with great rapidity, stains the skin and nails yellow. It is a powerful oxidizing agent, di olving most of the metals, after oxidizing them; but it is worthy of notice that when its sp. gr. is 1-487, it has not the least action on tin, though, if stronger or weaker, it oxidizes it rapidly, nitrous gas being evolved with almost explosive violence. It has very recently been obtained in the anhydrous state, which chemists long considered to be impo ible. It is in the form of six sided prisms, which are perfectly clear and colorle ; they become very hot in water, and di olve in that fluid without imparting to it any color or disengaging any gas. Nitric acid is obtained by acting on nitrate of potash, or nitrate of soda, with sulphuric acid, and distilling off the acid which is set free. Form. NO5. [s. 648]