In a marvelous manner these glands enlarge (hyperthrophy) to enable them to meet the extra demand made upon them when the toxins in the body are in excess of their normal capacity to meet and destroy. This enlargement often takes place in a very short time and may be noted by everyone following the bite of poisonous insects or reptiles or following infection. When they enlarge this increases their capacity for work.

The liver appears to be the chief organ of the body engaged in the production of urea. Urea is manufactured out of certain compounds that result from the break down of protein substances and which are constantly present in the blood, coming either from the regular wear of the body, due to its activities, or from the intestines.

Destructive disease of the liver--acute yellow atrophy, suppuration, cirrhosis, etc., and acute phosphorus poisoning--largely diminish the production of urea but increase the quantities of the cell wastes from which urea is produced. This work of the liver in preparing cellular waste for excretion is an exceedingly important one, as, upon the successful accomplishment of this work depends, to a great extent, the success of the kidneys in their work of excretion.

Very similar to and closely associated with urea formation is the conversion, by the liver, of toxic compounds, products of putrefaction of proteins, into non-toxic compounds. These substances--indol, skatol, phenol, and cresol--are absorbed from the intestine and carried to the liver through the portal vein. The liver cells deprive them of their toxicity, after which they are allowed to enter the blood from whence they are excreted by the kidneys. Other toxic substances, as, for instance, alcohol, are likewise reduced in toxicity in the liver. However, the methods by which this is accomplished vary with the varying natures of the compounds. The liver thus forms. a chemical laboratory and presents a chemical defense against the entrance into the blood and general circulation, of agents that are more or less toxic.

Special means of elimination are devised in certain conditions in which the ordinary channels of excretion are inadequate, or inefficient. For instance, abscesses everywhere in the body are limited and walled off by the formation of a thick wall of granulation tissue. Gangrene is also walled off in the same manner. The necrosed portion then sloughs off, nature grows new tissue to take the place of the destroyed tissue and the place is healed.

Acute inflammation of the liver usually terminates in resolution, but sometimes in suppuration with abscess formation. This is more likely to be the case in hot] climates. The amount of matter discharged from an abscess of the liver is sometimes enormous and it is wonderful to see in what ways nature operates in getting rid of it.

There are several channels through which the pus may be sent out of the system. The inflammation may extend upward until an adhesion to the diaphragm is accomplished. A dense wall of scar tissue is first formed around the abscess. The abscess then extends through the diaphragm to the lungs, which become adherent to the diaphragm. Liver, diaphragm and lungs form one solid piece. A tight union of these organs prevents the pus from pouring into the peritoneal or pleural cavities. A hole is eaten through the lung, the pus is poured into a bronchial tube, is coughed up emptying the abscess and leaving a clean hole. The wall of scar tissue thrown up around the path of the abscess grows stronger and contracts until, finally, only the scar remains, it having closed the hole, and the patient is well.

The abscess may be directed downward or to the side of the liver. In such a case the process is the same, except the liver becomes united by adhesions, produced by inflammation, to the stomach or intestines or to the wall of the abdomen. If it adheres to the stomach or intestine the abscess will perforate into these and the pus pass out in the stools. If it becomes adherent to the wall of the abdomen the abscess will "come to a head" under the skin and the pus will be discharged on the surface of the body. In either case cicatrization follows and the patient is well. In some cases the abscess discharges into the gall-bladder and passes from here into the intestine. It has also been known to "point" on the back.

It sometimes happens in weak individuals that nature is not able to make proper connections along the line of march and the pus finds its way into the pleural cavity causing empyema; or into the abdominal cavity where it results in peritonitis and, usually, death.

Another daring engineering feat is often accomplished by nature in the case of gallstones that are too large to pass through the bile duct directly into the small intestine. She frequently causes the gallbladder to adhere, by means of inflammation, to the wall of the intestine, an ulcer forms, making a hole through both the wall of the gall-bladder and that of the intestine. The stone slips through into the intestine and passes out with the stools. The hole heals up and all is well again. In other cases the stone may be sent out through the abdominal wall and skin, on the outside of the body.

A similar manifestation of the body's self-healing, self-adjusting, self-repairing powers, is seen in the common accident whereby a sliver becomes embedded in the flesh. If it is not removed immediately, the forces of life perform a skillful little piece of engineering and remove it for us. Pain and inflammation are soon followed by the formation of pus, which breaks down the tissues towards the surface of the body. Gradually increasing in amount, the pus finally breaks through the overlying skin and runs out, carrying the sliver along as a souvenir. A piece of necrosed bone, in the femur for instance, in a tubercular hip, will be worked up through the thigh and cast out along with the pus. The process by which the bone is expelled from the body is similar to or identical with the process by which the sliver is expelled from the flesh.

In inflammation of the kidneys, due to the impairment of kidney function, the normal constituents of the urine are decreased. They remain in the blood instead of being eliminated. Due to the necessity of removing from the circulation, the salts, etc., that are normally eliminated through the kidneys, and to the necessity also, of keeping these in dilute solution so long as they remain in the body, and to the equal necessity of removing them from the circulation, dropsy develops in various portions of the body, but particularly in the tissues immediately under the skin. It may also collect in the cavities of the body. When kidney function is restored the dropsical fluid is gradually absorbed into the circulation and eliminated.

In this connection, also, may be mentioned the power of the living body to manufacture or secrete protective substances. Pour common salt over a shell-less land-snail or gastropod (slug) and it will instantly secrete a substance that rapidly diffuses throughout the salt, giving it the appearance of finely ground egg yolk that had been boiled hard previous to grinding. Poisonous and irritating substances coming in contact with the lining membranes of the hollow organs of the body or gaining access to the eye, are met with an immediate out-pouring of mucous or tears which both envelopes and dilutes these, rendering them more or less inert, and then washes them away.