706

Pills.

part III.

which is to be directly divided into four hundred and eightyequal-sized pills."

One grain of mercury is contained in four grains of the mass,made according to the London and Dublin formulae, and inthree grains according to the Edinburgh.

In these preparations the mercury is first minutely dividedby the viscosity of the conserve, the substance with which itis triturated: and formerly it was believed that this mechani-cal division was all that was effected by the trituration. It isnow, however, generally, and with much probability, supposedthat the metal is oxidized; and that the great extension of sur-face, and in some degree the substance used in the trituration,facilitate this effect. Syrup, honey, mucilage, soap, guaiac,and other matters, have been occasionally employed ; but theColleges have agreed in preferring conserve of roses; and it isnot improbable that the operation is shortened by the weakacid which the conserve contains. On -the continent the oilof eggs has been employed for dividing mercury 1 , and certainlyno substance so rapidly assists in producing the desired effectthis oil, when it has been kept for some time. In the

as

above preparations, therefore, the mercury is nearly in thestate of the black oxide, and on this combination of oxygenits activity as a remedy altogether depends. The more assidu-ously the trituration is continued, so as to bring the surfacesof the globules of mercury quickly and repeatedly intoxontactwith the air, the more perfect is the preparation. The oxi-dizement of the whole of the globules, or the extinction orkilling of the mercury, as it is termed in the common languageof the laboratory, is known to be completed, when on rubbinga small portion of the mass with the point of the finger on apiece of clean paper, no metallic globules are perceptible. Themass must be then immediately formed into pills, as it veryrapidly becomes too hard, if allowed to remain.

Medical properties and uses. —These pills are stimulant andantisyphilitic, and are the most common form of preparationunder which mercury is exhibited for the cure of venerealaffections, being much less liable to act on the bowels than anyof the other forms. The common dose is grs. v;. to grs. viij.or two pills, given twice a day until the mouth be affected.Larger doses are apt to excite purging.

PILULE HYDRARGYRI SUBMURIATIS COM-POSITE. Lond. Edin. Pills ofSubmuriate of Mercury.

" Take of submuriate of mercury (calomel), precipitatedsulphuret of antimony, of each a drachm ,• guaiac gum-resin,

1 Vide Lond, Med. Repository, vol. v. p. 166.