fresh savin (leaves bruised), 2 parts; boil together until the leaves become crisp, then strain, with pressure, through a linen cloth.
2. (Ph. L. 1836.) Lard, 2 lbs.; savin leaves, 1 lb.; beeswax, 1⁄2 lb.; as last.
3. (Ph. L. 1851.) In the B. P. this preparation is included among the OINTMENTS (which see); in trade, however, the old name (Ph. L. 1836) is still generally retained.
Obs. The preparation of this cerate requires caution, as the active principle of the savin, being volatile, is injured by long boiling and a high temperature. The leaves are usually boiled until they are crisp, but as this takes some time, the essential oil, and consequently the odour, is nearly all dissipated. A better plan is to express the juice from the leaves, and to add it to the wax and oil melted together, and just beginning to cool. As usually met with in the shops, this cerate has a lively green colour, and the odour of the fresh plant; but neither of these is derived from the leaves in the common process of making it. The first is caused by the addition of powdered verdigris, and the last by adding a little of the essential oil of savin to the compound when nearly cold. The preparations of the British Colleges have only a very pale green colour, and even that rapidly changes by exposure to the air. A uniform green colour may therefore be regarded as a proof of adulteration; as the unadulterated compound, however, skilfully prepared, is of a dingy green colour, of little intensity; and after it has been made a short time, it fades on the surface, and the under portion becomes streaky and mottled. A greater quantity of colour is obtained from the leaves by long digestion in the fat and wax in earthen vessels, at a moderate heat, than by hasty boiling. In this way a lively green is sometimes produced, but it rapidly changes in the manner just mentioned.
The following forms are those commonly adopted by the wholesale druggists for the manufacture of this cerate:—
4. Lard and suet, of each 6 lbs.; yellow wax, 2 lbs.; melt them together in an earthen vessel; add 2 oz. of distilled verdigris (previously rubbed down smooth in a mortar with an equal weight of sweet oil); strain, whilst hot, into a large earthen pot, and when the whole has cooled a little, add of oil of savin, 1 oz., and stir until cold.
5. Savin leaves, 4 lbs.; yellow wax, 2 lbs.; lard, 8 lbs.; boil until the leaves become crisp; then strain, and add, of green ointment (lively coloured), 5 lbs.; when cooled a little, further add, of oil of savin, 3 dr., and stir briskly until cold. Prod., 131⁄2 lbs.
Uses, &c. Savin cerate and ointment are chiefly employed to keep up the discharge from blisters (perpetual blisters), for which purpose it is preferable to preparations of cantharides. The practice of colouring this cerate with verdigris, which is general in trade, cannot be too severely censured, as its therapeutic action is thereby altered. The copper may be detected by burning down a little in a platinum or Hessian crucible, washing out the ashes with a little dilute nitric acid, placing the liquor in a glass tube, and applying the usual tests. See Copper and Ointments.
Cerate, Sim′ple. Syn. Cera′tum sim′plex, L. Prep. 1. (Ph. E.) Spermaceti, 1 part; white wax, 3 parts; olive oil, 6 parts; melt by a gentle heat, and stir until cold. This preparation is similar to Simple Ointment (Unguentum Simplex), B. P. (which see).
Cerate of Snails. White wax, 3 parts; spermaceti, 3 parts; oil of almonds, 32 parts; mucilage of snails, 24 parts; otto of rose, sufficient to scent it.