This section is from the book "A Treatise On Therapeutics, And Pharmacology Or Materia Medica Vol1", by George B. Wood. Also available from Amazon: Part 1 and Part 2.
When the effects of nitrate of silver upon the system generally are desired, it should be given preferably in the form of pill; as a larger dose can thus be taken, without irritating the stomach, than in solution. The same form is also preferable when it is given by the mouth for intestinal affections; as there may be some hope that it may thus, in part at least, escape decomposition by the gastric contents. For its alterative influence on the stomach, it may be given in either form; but the solution would probably be most effective if well borne. When taken in pill, it should be mixed up with flour, starch, or powdered gum, with syrup. The crumb of bread, often used, is objectionable on account of the common salt it contains. If given in solution, distilled water should be employed as the menstruum; the taste being covered, if deemed advisable, by a little oil of mint or peppermint. In either case, the preparation should not be long kept before being used.
The dose to begin with, at least in delicate states of the stomach, should not exceed one-quarter or one-third of a grain, three times a day, which may be gradually increased to one, two, or even three grains, should no irritant effect be experienced. Some have pushed the medicine much further, even so far as fifteen or twenty grains, and with impunity; for there are generally in the stomach substances, especially the chloride of sodium, which render it inert by decomposition; and it might unite with the albumen of the mucus, or even superficially with that of the epithelium itself, without serious injury. But these decomposing substances might be wanting, or the mucous coat might be unprotected by its ordinary secretion, and the medicine come into contact with some exposed point with too great intensity; in short, experience has shown that the salt may prove highly irritant, and even poisonous; and there is no occasion to incur any risk, for, as before stated, these large doses are almost wholly decomposed, and pass out of the bowels; a very small portion only being absorbed; so that, when not mischievous they will probably be useless.
The great point will be to guard against the discoloration of the skin. For this purpose, the mouth should be carefully and frequently observed, and the least appearance of a dark bluencss in the gums should be considered as a signal for discontinuing the medicine until this has disappeared. As the nitrate in solution might have the effect of darkening the surface of the mouth by its direct contact, the discoloration thus produced must not be mistaken for that resulting from the absorption of the medicine. Dr. James Johnson states that no ease of discoloration is on record, in which the use of the medicine has not been continued beyond three months.* It would, therefore, be a good rule, after having employed it continuously for that length of time, to suspend it for a period, say one or two months; and there is some ground for this suspension in the long retention of the medicine in the tissues, as shown by the experiments of Orfila; so that, though it should be omitted, that already taken and absorbed might still be acting.
The medicine should be taken on an empty stomach, and the caution should be observed that nothing containing common salt, or any other substance having the property of decomposing the nitrate, should be swallowed within a short time, either antecedent or subsequent to its administration.
The following are preparations of silver derived from the nitrate.