Abstract
It is only during recent years that it has become possible by the use of new technic to detect molecular phenomena produced in the mechanical deformation of substances. As far as metallic substances are concerned, and crystalline substances in particular, the problem has already been solved for the most part. On the other hand, in spite of considerable progress during recent years the study of the deformation of organic substances and of fibers in particular, in which group rubber is included, has not yet been carried on. The mechanical properties of a crystalline system vary according to whether there is a single crystal or an aggregate of crystals. However, in both cases the extensibility of the products originates in a displacement of parallel layers, i. e., a sliding of the parts of the crystal along definite crystalline planes, this phenomenon of sliding being irreversible in these substances. In fact, in these cases the reversible part of the elongation is very weak, and amounts to only a few thousandths of the entire phenomenon. In brief, the phenomena of hardening brought about by deformation (sometimes observable) are due to disturbances of the regular lattice. In particular, the displacement of the atom and the change from its normal position can cause the appearance of irregularities on the surface of sliding.
Semi Regular Lattice Polyhedra
