t above the anal orifice (as
shown in the illustration referred to); and a constricted and irritable
rectum results in the impaction and dilatation of the sigmoid cavity,
which is normally a receptacle, closed at its lower end by circular
fibres separating it (the cavity) from the rectum and performing the
function of a sphincter muscle. The rectal muscular fibres perform the
office of a sphincter for the sigmoid cavity. The pathological changes
that result in rectal impaction of feces usually extend to the sigmoid
cavity. This cavity is 17-1/2 inches in length, shaped in a double
curve like an italic _S_. Civilized man should consider the disturbance
to the functional action of body and brain, and the danger to health
and longevity involved in the storage of effete and fetid matter. The
disturbance and danger are enhanced when the tissues of the sigmoid
flexure and the rectum are invaded by inflammation. A healthy action of
the sigmoid receptacle depends on the rectum (a conduit six to eight
inches in length); and as it is the universal verdict that disease of
the rectum is one of the most common maladies that afflict the human
race, it must inevitably follow that the feces will be abnormally
stored in the sigmoid cavity, occasioning thereby habitual constipation
which in turn brings on a host of functional disturbances throughout
the system.

The colon is a receptacle and a conduit some three feet in length (see
ib. p. 13) and its action depends upon the ability of the sigmoid
flexure to perform its function as a final normal receptacle; and this
in turn upon the rectum, which depends on the sphincter ani. The colon
does not appear to possess any digestive powers, though it is capable
of absorbing substances. Its function is not only to receive and
forward the trifling residue of food which escapes digestion and
absorption, but chiefly to excrete, through its own minute glands, the
waste of the system coming from the blood.

The excretion from these glands of the colon into the colon, plus the
effete portion of the food received by the colon from the small
intestine, approximate in weight from four to six ounces in an adult
person in twenty-four hours; and of this amount passed 75 per cent is
water; so that were the excreta dried the solid matter thus evacuated
would not be found to weigh more than one ounce, or one and a half
ounces.

CHAPTER IV.

INDIGESTION, INTESTINAL GAS, AND OTHER MATTERS.

We not