Complete Works, Vol. V

...divided or opened for the reception of nourishment. Furthermore, if it used nourishment, it would have to possess some part that first draws the nourishment, such as roots in plants or the mouth in sentient beings; however, we see nothing of this sort in stones. Nor is it correctly said that the soul of a stone is oppressed by earthiness, and therefore cannot exercise life and sensation, as many of the physiologists have claimed. For according to this, nature would be deficient in necessities by not giving the stone the organs by which it might express its necessary operations. Therefore, stones do not have souls, but rather other substantial forms given by celestial virtues and the proper mixture of elements. For the most part, these forms are unnamed; nevertheless, their differences rely upon the various names of stones when they are called tufa, pumice, flint, marble, sapphire, emerald, and the like. Since these are hidden from us, we do not have proper definitions of stones except by circumlocution, taking accidents and signs in place of definitions. But we know these things, as they are diversities of a mobile and transmutable body in a simple sense, and the mixture that a stone is belongs to the genus of mixtures. Since a mixture is divided into a mixture only, and a complexionated mixture referring to a balanced temperament of qualities, we know a stone to be in the genus of non-complexionated mixtures. Gathering then from all that has been said, we say a stone is a non-complexionated mixture coagulated by the power of minerals into a form. From these, it is further manifest that a stone is more of a homogeneous nature than one possessing life, even though the different natures of the elements are essentially present within it. For this reason, the science of complexionated things is to be preferred over the science of stones. There are many forms of stones, such as, in the genus of marble, porphyry, alabaster, and the like. Similarly, it is the same in other genera of stones, which it is not useful to pursue, because their forms will be made manifest below through the accidents of the body and hardness. For these accidents are their properties, and once these are known, their nature is sufficiently manifest. Concerning the end, however, one must not ask, because form is the end in physical matters. Therefore, since we believe we know each thing when we know its essential and proper causes, the nature of stones is now universally known in a general sense. Nevertheless, because the place of generation is a principle, as was determined in the preceding sections, we must, along with what has been said, know about the place of the generation of stones, for the place is a certain efficient cause of the stone, to which the formative virtue of the stone is first given.

CHAPTER VII.

Let us therefore make mention of the places in which stones are generated, either always or frequently, and let us inquire into the virtue of the places and their differences. We see that many stones are found on the banks of perennial waters, and we recognize through this that the banks of certain waters are places generating stones. However, these kinds of banks differ, for some produce stones more quickly, some more slowly. In certain places on the banks of the river that is called the Glon a legendary or obscure river name, stones are generated in the space of thirty-three years, as Avicenna and certain other philosophers testify. Yet not every water is generative of stones on its banks, because water from corrupted, marshy earth corrupts rather than generates stones. As we see in certain regions, where even if the places are watery, they do not, for the most part, generate stones. Furthermore, we will frequently find mountainous places that are stony, from which we recognize that in mountainous places lies the location for the generation of stones. However, we sometimes find mountains without stones, but those are frequently neither large nor associated with other mountains; rather, they are found solitarily, so that perhaps there is only one, or at most two or three. But whenever many mountains are associated with one another, then stony mountains are found, and many stony mountains are also sometimes found in flat land of solid surface. This cannot happen everywhere, and those places are generative of stones. Furthermore, stones are very frequently generated in waters, which cannot be explained except that those are the place for the generation of stones. A sign of this is that there are certain waters from which stones are generated when they flow over their banks where they run; and if they are poured over another place, stones are not generated from them. It has been experienced in the Pyrenees that there are certain places where rainwater is converted into stones; if this same water is poured elsewhere, it remains water and is not transmuted. Similarly, wood lying in certain waters and seas is converted into stones and retains the shape of the wood. And sometimes plants born in those waters and seas are so close to the nature of stones that, as if dried in the air, they assume the form of stones.