Why the pharmaceutical use acid and my knowledge of other incarnation

And is that how we take the 'principle active' of most of the leaves, of course, have plants that the medicine could be in other parts of the plant like the wood or root, but of the leaves when I work with it was that way, was put the leave in a glass bottle and have to be well shut with the time the leave will get dry inside the bottle and the active principle would be volatile inside the bottle so the principle would be as gaseous state inside the bottle so I have to agglutinate before the bottle be open or will get lost for the air, and with acid the result is in the same day, the acid corrode all the leave but not the active principle and the result is a white powder, like that ones that you see to make the pills that are compressed, the principle will be combine with the acid like a salt, is more fruitful, and hold more principle active that the volatile of the leaves. Rute Bezerra de Menezes Gondim