Preparations. - By rubbing up chalk (2) and mercury (1) together, B.P. By rubbing up mercury (38), chalk (50), and sugar of milk (12) together, moistening them with a mixture of equal parts of ether and alcohol, U.S.P.

Characters. - A powder of light-grey colour; free from grittiness; insoluble in water; partly dissolved by diluted hydrochloric acid, leaving the mercury in a finely-divided state.

Impurity. - Mercuric oxide.

Test. - The solution formed with hydrochloric acid is not precipitated by the addition of chloride of tin.

Dose. - 3 to 8 grains.

Uses. - It has been much recommended by Ringer as a remedy in many diseases both of adults and of children. In simple tonsillitis, or the inflamed throat of scarlatina, or in mumps, he recommends a third of a grain every hour, and the same dose three or four times a day will, he says, clean the tongue, remove the disagreeable taste from the mouth, and improve appetite and digestion in the dyspepsia occurring in chronic disease or commencing convalescence. A similar dose will cut short an attack of jaundice, with vomiting and pale stools, occurring in nervous persons after exposure to cold, fatigue, or excitement; and half a grain thrice a day will restore the colour to the stools and remove the dyspepsia in patients suffering from acidity, flatulence, and vomiting in the morning. Diarrhoea in children, accompanied by pale, offensive motions, or by muddy, or green - coloured, or curdy stools, whether accompanied by sickness or not, is successfully treated by similar doses of this remedy. It may also be used to produce the general action of mercury combined with opium or Dover's powder.

B.P. Pllula Hydrargyri. Mercurial Pill; Blue Pill (p. 522). 3 grs. contain 1 of mercury.

Dose. - 3 to 8 grains.