An atom is one of the ultimate particles composing a molecule. A complex molecule is one in which two or more elements have been combined. Example: water molecules are formed by two atoms of hydrogen and one atom of oxygen.

A ferment is a substance causing fermentation in other matter with which it comes in contact. There are two kinds of ferment expressed by the names organized and unorganized.

Unorganized ferments are chemical substances having the power to produce or assist in the production of fermentation.

Organized ferments are bacteria having the power to produce fermentation.

Fermentation means the process through which complex molecules are decomposed and their ingredients disassociated by the action of ferments. As an example of fermentation, we can take proteid food substances, the molecules of which are always of complex form, and by subjecting them to the action of organized ferments (bacteria), decompose them, and separate each gas ingredient, obtaining therefrom a variety of gases from what was formerly a substance of perfect chemical union. Fermentation is present in most of the natural processes whereby chemical changes are produced in animal and vegetable matter. Fermentation is taking place all the time in all the climes excepting possibly the frigid zones. The organized ferments (bacteria) are subject to the same temperature limits that govern the reproduction and the growth of all bacteria.

Fermentation is divided into spirituous fermentation, digestive fermentation, metabolic fermentation, and putrefactive fermentation.

Spirituous Fermentation.

—Spirituous fermentation is that process of fermentation by which forms of yeast cells, by their growth and reproduction in such complex substances as grapes, fruit, apple juice, grains, etc., extract alcohol from these substances and by this process produce wine, cider, spirits, etc. Many times in the dead body, spirituous fermentation occurs. Spirituous fermentation is caused by a vegetable parasite called yeast.

Digestive Fermentation.

—Digestive fermentation is that process by which digestion and nutrition in the living body is assisted through the action of ferments called enzymes, acting on the food substance. This process is mainly one where each food particle is split up by a particular ferment or enzyme. After death this process may continue for a certain length of time and result in the formation of gas. Digestive fermentation is mostly chemical.