The most powerful and reliable preventive and solvent, thus far, is hydrargyrum. It is true that many voices have been raised against it, but from Bard, Bretonneau, and Billard to Rauchfuss, Ch. West, Lynn, Pepper, and others, the remedy has had its admirers. Large single doses of calomel have been given by some, amounting to 15-30 grains (gramme 1.0-2.0), but that treatment has not found many friends. In small and frequent doses it has been of good service to me both in fibrinous laryngitis and bronchitis, {105} particularly in the latter; gr. ¼-½ may be given every half hour or every hour. Tartar emetic is liable to develop so many unfavorable effects that even doses--in combination with calomel--of 1/100 of a grain require great caution. The most reliable mercurial preparation, in my experience, and the least hurtful, is the corrosive chloride. In the stomach it combines with the chloride of sodium, is absorbed without being changed, and transmuted into an albuminate during its circulation in the blood. Babies of tender age bear one-half of a grain and more, daily, many days in succession. Salivation and stomatitis are exceedingly rare after its use. Gastro-intestinal disturbances are not at all frequent; diarrhoea, if observed at all, is very moderate, and can be avoided or removed by the administration of mucilaginous and farinaceous food or a mild dose of an opiate. But the administration of the bichloride requires care in regard to its solution. A fiftieth of a grain may be safely given to a baby a year old every hour, but it must be dissolved in one-half of a tablespoonful or a whole tablespoonful of water. The solution of a grain in a pint of water is about correct. In those very rare cases in which no preparation of mercury is borne internally the inunction of sufficient and frequent doses of the oleate of mercury may take the place of the internal administration or alternate or be combined with it. The blue ointment is not so effective as the oleate. The subcutaneous injection of the corrosive chloride may be added to the modes of administration if no time must be lost in introducing as much as possible of the drug into the system. Now and then, however, the subcutaneous tissue of the child does not tolerate it well in that form, though the solution may be not larger than 2 per cent.[3] The cyanide of mercury, in doses of a hundredth of a grain every hour, has been warmly praised by A. Erichsen and C. G. Rothe. [Footnote 3: _The Medical Record_, May 24, 1884.]