Calomel, from its general stimulant power, may readily be supposed to affect the intestines more considerably than the milder mercurial preparations; and, in fact, it is found, that, in many cases, it much more readily excites looseness than they do. From this circumstance, it can be less easily introduced into the system, especially if the alimentary canal possess uncommon irritability. If these assertions with regard to this mercurial preparation be well founded, it will be easy to determine in what cases calomel is preferable to other mercurials, and in what it is to be considered as less proper. It cannot be considered as well adapted for those inveterate and obstinate cases in which a long and gradual use of mercury is requisite, and to overcome which it is necessary that a considerable quantity of mercury should be accumulated in the circulating system. On the other hand, if the intestines are not very irritable, it will be particularly serviceable, in many recent cases, in which a speedy action of mercury is adviseable; and, in those where the venereal virus has not yet made its way into the circulating system, but is detained in the lymphatic, or in the mucous glands. From its sudden evacuant power, it may likewise be of great service where mercurials in the venereal disease are intended to be conjoined with an antiphlogistic course, or to make a part of it. What has been said of calomel may be considered as sufficient, with regard to the milder part of the saline preparations. It now only remains, then, that some observations should be offered on corrosive sublimate, which is the most acrid of these that is usually employed internally. Corrosive sublimate, it has already been observed, is the basis of the preparation last treated of. But, in this preparation, the mercury, from the proportion of muriatic acid which is united with it, is in a very acrid state. When taken in substance, even in a very inconsiderable quantity, it proves a virulent poison to the human frame. To this circumstance it was probably owing, that, for a very long time, it was used only for external purposes, and even then, from its high stimulant power, not without the greatest caution. But the many inconveniencies attending salivation, which was at the same time found to be by no means absolutely necessary to a cure, induced practitioners to make trial of preparations less apt to have that effect, than those which had formerly been used. As every preparation of mercury, in proportion to its acrimony, has a greater tendency to act upon the surface, and less to affect the salivary glands, it is not surprising that corrosive sublimate should at length have been proposed.