There are certain characteristics common to all the mineral acids which claim primary attention:

Concentrated mineral acids are caustic to a greater or less degree.

They combine with alkalies and alkaline earths to form salts, and unite with vegetable acids, setting them free from their combination with bases. When in contact with the tissues of the body they combine with the protoplasm, neutralizing the alkalies which the latter contains and forming mineral salts. They also combine with the albumin, forming acid albumin.

They diminish the functional activity of the muscular and nervous systems. Applied locally in a concentrated form, or taken internally in poisonous doses, they tend to produce rigidity of the muscles by coagulating the myosin.

The alkalinity of the blood is lessened, ammonia and the fixed alkalies of the blood and cells being called on to counteract the action of the acid, and the acidity of the urine is increased by the internal administration of practically all of the mineral acids.

They increase the secretion from alkaline glands and lessen the secretion from acid glands.