Dilute Hydrochloric Acid: Spirit of Salt Poured into Water

A weak acid, used for example to dissolve the calcium salts out of bones before gelatin is boiled from them. Read the strength of your spirit of salt with a hydrometer, then pour the acid into the water, slowly, never the water into the acid. We make it about 5 % by weight. Work outdoors or by an open window: strong hydrochloric acid fumes. The picture: our diagram, acid poured into water.