Further, the eye is endowed with polarity, by which its activity is divided into two parts qualitatively distinct.
What exists as a substance and the basis of qualities or forms (quod est) may be said substare; the forms on the other hand by which such an individual substance exists qualitatively (quo est) subsistent, though it cannot be said that they substant.
Soc., 1890, 47, p. 364), who found that a film of olive oil spread over the surface of water produced a perceptible effect on small floating pieces of camphor, at places at which the thickness of the film was io 6 X10 -8 cms., but produced no perceptible effect at all at places where the thickness of the film was 8.1 X10 -8 cms. Thus a certain phenomenon, of the nature of capillary action, is seen to depend for its existence on the linear dimensions of the film of oil; the physical properties of a film of thickness Io 6Xio 8 cms. are found to be in some way qualitatively different from those of a film of thickness 8.1 X io 8 cms. Here is proof that the film of oil is not a continuous homogeneous structure, and we are led to suspect that the scale on which the structure is formed has a unit of length comparable with 8 X10 -8 cms. The probability of this conjecture is strengthened when it is discovered that in all phenomena of this type the critical length connected with the stage at which the phenomenon changes its nature is of the order of magnitude of 10 -8 cms.
The Stahlian theory, originally a theory of combustion, came to be a general theory of chemical reactions, since it provided simple explanations of the ordinary chemical processes(when regarded qualitatively) and permitted generalizations which largely stimulated its acceptance.
These features, although exaggerated in the portion of the river now in question, are qualitatively characteristic of its entire course below the mountains.