Ancient Medicine of the Filipino
The Angono Binangonan Petroglyphs are 127 human and animal figures engraved on the rockwall probably carved during the late Neolithic, or before 2000 BC. The engravings are mostly symbolic representations and are associated with healing and sympathetic magic.
Researchers have argued that the figures were medicinal and religious in function as they were made by ancestors to transfer the sickness of a child onto the limestone wall, thus, curing the child from ailments.
From ancient method of healing as described in the above mentioned article that can be found in Wikipedia, the Art of Ritual Tawas has the same function aside from diagnosing the cause of illness but at the same time absorbing the negative energies and illness of the person into the medium that been used.