Quick bread leavening process, agents (one or more food-grade chemicals—usually a weak acid and a weak base) are added into the dough during mixing. These agents undergo a chemical reaction to produce carbon dioxide, which increases the baked good's volume and produces a porous structure and lighter texture. Yeast breads often take hours to rise, and the resulting baked good's texture can vary greatly based on external factors such as temperature and humidity. By contrast, breads made with chemical leavening agents are relatively uniform, reliable, and quick. Usually, the resulting baked good is softer and lighter than a traditional yeast bread. Chemical
Substance theory which "we can understand nothing else than an entity which "is" in such a way that it need no other entity in order to "be"." Therefore, only God is a substance as "Ens perfectissimus" (most perfect being). Heidegger showed the inextricable relationship between the concept of substance and of subject, which explains why, instead of talking about "man" or "humankind", he speaks about the "Dasein", which is not a simple subject, nor a substance. Alfred North Whitehead has argued that the concept of substance has only a limited applicability in everyday life and that metaphysics should rely upon the concept