32. Here one could say: “But if all the species of plants and also the minerals, especially in the hot zones, contain so much of the sun’s light substance, no further artificial methods would be needed to draw from the sun what can easily be obtained in quite a natural way.

33. This is true, and so far most medical practices have been based on this.

34. Whoever uses known healing herbs will certainly always feel their effect. But no healing herb exists which is able to absorb all the healing substance from the sunrays. Every plant absorbs only what is homogeneous to it and cannot absorb anything else, since its structure is such that it can absorb from the sunlight only what is required by it.