minutes only, was not found to have sensibly less restraining effect than
when infused for thirty minutes. On peptic digestion both tea and coffee
had a powerful retarding effect. When of equal strength cocoa was nearly
as bad, but as it is usually taken much weaker, its inhibitory effect is
of little consequence.

Bacteria are minute vegetable organisms, which exist in the dust of the
air, in water and almost everywhere on or near the surface of the earth.
They are consequently taken in with our food. They exist in the mouth;
those in carious teeth are often sufficient to injuriously affect
digestion and health. The healthy gastric juice is to a great degree
antiseptic, but few bacteria being able to endure its acidity. When the
residue of the food reaches the large intestine, bacteria are found in
very great numbers. The warmth of the body is highly favourable to their
growth. They cause the food and intestinal _debris_ to assume its fæcal
character. Should the mass be retained, the bacterial poisons accumutate
and being absorbed into the body produce headaches, exhaustion,
neurasthenia and other complaints. Proteid matter, the products of its
decomposition and nitrogenous matter generally, are especially the food of
bacteria; this is shown in the offensiveness of the fæces of the
carnivora, notwithstanding their short intestines, compared with that of
the herbivora. Also in the difference of the fæces of the dog when fed on
flesh and on a nearly vegetable diet. On a rich proteid diet, especially
if it consists largely of flesh, the bacterial products in the intestines
are greater than on a vegetable diet. On the latter such a disease as
appendicitis is rare. Professor Elie Metchnikoff, of the Pasteur
Institute, thinks that man's voluminous and highly developed large
intestine fulfils no useful purpose, and on account of its breeding a very
copious and varied bacterial flora, could with advantage be dispensed
with. He also has said that man, who could support himself on food easily