fermentable
liquid. The yeast cells grow and multiply at the expense of the
sugar, in destroying which they produce alcohol, carbonic
dioxide and other substances. When the alcohol amounts to some
17 per cent. of the liquid the process is stopped by the
poisonous action of the alcohol on the yeast cells. In just the
same way the toxines produced by the bacilli at length stop
their further multiplication and put an end to the disease.
Alcohol is in fact, the toxine produced by yeast, and, like many
other toxines, it is not only poisonous to cells which produce
it, but to any animal into whose veins it may happen to get.

"There can be little doubt that the state of immunity which one
attack of certain fevers confers against future attacks depends
partly upon what is called the phagocytic action of leucocytes.
These have been actually observed to draw into their interior
and destroy bacilli which would otherwise have multiplied and
produced their special effects. There can be little doubt,
either, that we are continually taking into our systems bacilli
of all sorts, and that, again, disease is averted by the
activity of the germ-devouring leucocytes. Dr. Broadbent
describes an experiment which proves that power of resisting
disease is largely dependent on the activity of these cells. A
rabbit, having had a certain quantity of bacilli injected under
its skin, suffers from inflammation at the spot, and perhaps
abscess, but recovers. At the same time, another rabbit is
treated in precisely the same way, but, simultaneously, a dose
of chloral is injected into another part of the body. The
chloral, circulating in the blood, is known to paralyze
leucocytes, and, as a result of this, they do not collect and
wage war on the bacilli injected under the skin; there is very
little local reaction, the bacilli get free course into the
lymph and blood, and the animal dies. But, in the words of Dr.
Broadbent, 'alcohol in excess has a similar action on the
leucocytes, and this, as well as the deteriorating influence of
chronic alcoholism on the tissues, predisposes to septic
infection. A single debauch, therefore, may open the door to
fever or erysipelas.' A similar experiment of Doyen confirms
this. He found that guinea pigs can be killed by the cholera
microbe, when introduced by the m