All known inorganic forces act identically with respect to _living_ as to _dead_ nature. We have seen that forces are nothing but qualities and motions of the smallest particles of matter, the atoms, with which these forces are invariably and inseparably conjoined. An atom therefore under all circumstances can only perform the same work, develop the same forces, produce the same effects, whether it belongs for the moment to an organic or to an inorganic composition. Respiration, digestion, the process of growing and segregation are all chemical reactions. Oxygen, hydrogen, carbon and nitrogen are composed and decomposed within the organic body in accordance with the same laws that govern them outside. We have also learned more perfectly how nourishment is transformed into organic tissues, and we know that through different channels it leaves the body in precisely the same quantity as it entered, partly unmodified and partly in other forms and compositions. No one atom has meanwhile been lost or become another. Digestion is a purely chemical process. The stomach of an animal may well be compared to a chemical retort, where the substances there mixed are decomposed and composed exactly according to the general laws of chemical affinity. These facts, which may be multiplied _ad infinitum_, enable us to understand that the difference between organic and inorganic is non-essential, and that therefore every living being may be considered a chemical laboratory, whence we arrive at the following result: _Because daily experience teaches us that all organisms consist of the same atoms as does inorganic nature, although in different compositions, therefore no specific organic force, no life-force, can exist. This latter is not a principle, but a result._ When organic substance assimilates inorganic and brings it into its own characteristic condition, this is not done through a specific force, but through a kind of infection, whereby the molecular conditions in the organic substance are transferred to the inorganic.