As the actions and uses of the mercurial preparations have been sufficiently discussed elsewhere, little need be said in addition as respects their applications as purgatives.

Hydrargyri Chloridum Mite

Mild chloride of mercury. Calomel. Dose as a cathartic, gr. j—grs. x.

Massa Hydrargyri

Mercurial pill. Blue mass. Dose, grs. v— grs. xv, as a cathartic.

Actions and Uses

These mercurial purgatives are rather slow in their action. A dose at bedtime will usually operate during the course of the following morning. One grain of calomel or five grains of mercurial pill will produce distinct purgative effects in most persons in about twelve hours, unless there be considerable habitual torpor of the bowels. They are apt to cause griping pains, nausea, and even vomiting, when the purgative effects begin. First brownish and bad-smelling, and afterward greenish stools, supposed formerly to be characteristic of the mercurial action, are produced. Much heated discussion has arisen as to the cholagogue action of mercury. Without entering into details on this point, it may be admitted that bile-elements are found in the stools from the action of mercury, as they are unquestionably found in the stools caused by some other purgatives. The presence of bile-elements in the faeces discharged, only proves that mercurial cathartics swept them out with the other contents of the intestinal canal, and does not prove that an excitant action was exerted on the secretory function of the liver. The stored-up bile in the gall-bladder may be emptied into the intestine in obedience to a reflex influence transmitted from the intestinal mucous membrane irritated by the purgative. Experimental investigations must be invoked to determine the question whether mercurials actually stimulate the liver to the production of an increased quantity of bile. In another place the experiments of Hughes Bennett's Edinburgh Committee have been stated. Since the report of that committee has made its appearance, the very accurate and painstaking investigations of Rutherford and Vignal have been published. Röhrig had already determined as the result of his experiments that "with large doses (twenty grains for a dog) it rarely happened that the secretion of bile was recalled after it had come to a standstill, although this agent can increase the secretion when it is only diminishing." Rutherford and Vignal arrived at the following conclusions as the results of their experiments with calomel: "1. An increase of the biliary secretion followed the administration of two successive doses of ten grains of calomel in one case (Experiments 30). Diminution of the secretion was the only result of the same doses given under similar circumstances in other two cases (Experiments 31 and 32); and it was the most definite result of the administration of four successive doses of three grains in another case (Experiment 33). 2. In all the four experiments the calomel had a purgative effect. 3. Analysis of the bile secreted during the calomel purgation in Experiment 33 showed that, notwithstanding a diminution in the quantity of bile secreted, the percentage amount of solids had become less." The results of experiment render it probable that mercurials do not increase the secretion of bile in animals, but we are not without confirmatory evidence in the human subject. In the cases of biliary fistulae (accidental) observed by Westphalen and Ranke, no increase, but rather a diminution in the amount of bile, followed the exhibition of calomel in purgative doses.

That the purgative action of mercurials has a distinctive and peculiar quality, a vast clinical experience attests. The stools are rather different from those caused by other purgatives, and the therapeutical effects are, it is generally held, sui generis. Whatever peculiarity pertains to the purgative action of mercurials is probably due to the fact that they greatly increase the elimination of the products of waste, or retrograde metamorphosis of tissue, by the intestinal glandular apparatus.

As a purgative, the use of mercury is restricted to those cases in which a deficiency of bile is supposed to be the cause of the morbid state—clay-colored stools, jaundice from catarrh of the gall-ducts; and to those cases, singularly enough, in which bile is supposed to be in excess—biliousness, so called, jaundice from excessive production of bile, etc. For further remarks on the actions and uses of mercury the reader is referred to the section on remedies used to promote destructive metamorphosis.