absorption of irritating or poisonous matter, which is thus able to get into the blood. The muscles in the intestinal wall can be forced to contract by the taking of certain drugs, such as cascara. But a muscle that is forced to act when it is tired or overworked not only does not act naturally, but becomes more exhausted and incapable of recovering its natural power, just as whipping an exhausted horse makes it go faster for a bitbut to drop sooner in its tracks. The dose of a drug that forces these muscles to act has to be increased to cause them to act again, and so on until at last the muscles become almost paralyzed and refuse to respond at all to any such drugs, no matter what size dose is given. Failure, therefore, to secure a proper and necessary amount of moisture and mucus in the bowel to keep its contents soft and easily moved along is one great cause of constipation. The attempt is often made to remedy this by the use of what are known as salts! But a knowledge of how salts act will show very plainly that their effect is only temporary, and the results, quite as harmful as when purgative drugs are employed. Salts produce a temporary increase of fluid in the bowel by drawing into it fluid from the blood and surrounding tissues. But the blood or tissues from which water has been attracted must in turn attract water from the bowel to restore the balance. Thus the bowel contents are again allowed to become hard and dry and constipation is increased. Hence the result accomplished is only temporary, and the dose of the salts has to be made stronger and stronger, the bowels fail to move without it, and the resulting constipation is only aggravated instead of relieved. To deficient moisture and impaired muscular power of the intestinal tube is often added an actual obstacle or obstruction to 10