CHAP. XXVII. Of Cerats and Emplasters.
* 1.1SUch affinity there is in the composition of a Cerat and Emplaster, that oftentime; the one is taken for the other, as is usually done in Ointments and Liniments. A Cerat is a composi∣tion more solid and hard then an ointment,* 1.2 and softer then a plaster, having his name from Wax, which taking away the fluidness of the oil bringeth him to his consistence. The differences of Cerats are taken some from the parts by which they are called, as Ceratum st••machicum: some from the effects, as Ceratum refrigerans Galeni: Others from the simple medicaments which are the chief in the composition, as Ceratum Santalinum. The proper matter of Cerats is, new Wax and Oils, being appropriated to the grief of these, or those parts; so that Liniments and Oint∣ments do scarce differ from Cerats, if they admit of Wax: for if ointment of Roses should have Wax added to it, it were no longer an Ointment but a Cerat.
Cerats, which are made with Rosins, Gums, and Metals, do rather deserve the names of Em∣plasters then Cerats. And therefore Ceratum ad Hernias, we commonly call Emplastrum contra Rupturam. If that pain or inflammation do grieve any part, we make Cerats of plaster, dissolved with Oil, lest that the more hard, and heavy consistence of the Emplaster should be troublesome to the part, and hinder perspiration: and therefore laying aside the composition of Cerats, let us speak of Emplasters.
* 1.3An Emplaster is a composition which is made up of all kinde of medicines, especially of fat and dry things, agreeing in one gross, viscous, solid, and hard body, sticking to the fingers. The diffe∣rences of Emplasters are taken from those things, which the variety of ointments are taken from. Of those things which go into the composition of an Emplaster, some are only used for their qua∣lity and faculty, as Wine, Vinegar, Juices. Others to make the consistence, as Litharge (which according to Galen, is the proper matter of Emplasters) Wax, Oil, and Rosin. Others be useful for both, as Gums, Metals, parts of beasts, Rosin, Turpentine to digest, to cleanse, and dry. Of Emplasters, some are made by boiling, some are brought into a form without boiling; those which be made without fire, do sud•••••• ••y, nor are they viscous: they are made with meal and pow∣der, with some juice, or wit•• 〈◊〉〈◊〉 ••umid matter mingled with them. But plasters of this kinde may rather be called hard 〈◊〉〈◊〉, or cataplasms: for plasters properly so called are boiled, some of them longer, som•• 〈◊〉〈◊〉, according to the nature of those things which make up the composition of the Empl•••• ••herefore it will be worth our labor to know what Emplasters do ask more, or which less be•••• 〈◊〉〈◊〉 or roots, woods, leavs, stalks, flowers, seeds, being dried, and brought into powder, are 〈◊〉〈◊〉 be added last, when the plas••er is boiled as it were, and taken from the fire, least the virtue of these things be lost. But if green things are to be used in a composition, they are to be bo••led in some liquor, and being pressed forth, that which is strained to be mingled with the rest of the composition; or if there be juice to be used, it is to be bruised and pressed forth, which is so to be boiled with the other things, that nothing for the quality is to remain with the mixture, as we use to do in Empl. de Janna, seu Betonica, & Gratia Dei. The same is to be done with Mucilages, but that by their clamminess they do more resist the fire. But there doth much of oil and hony remain in their plasters when they are made. Those juices which are hardened by concretion, as, Alces, Hyp••cystis, Acacia, when they are used in the composition of a plaster, and be yet new, they must be macerated and dissolved in some proper liquor, and then they are to be boiled to the consumption of that liquor. Gums, as Opopanax, Galbanum, Sagapenum, Ammonia∣cum, must be dissolved in Wine, Vinegar, or Aqua vitae, then strained and boiled to the con∣sumption of the liquor, and then mixed with the rest of the plaster. And that they may have the exact quantity of Guns, and Pitch, it is necessary that first they be dissolved, strained, and boiled, because of the sticks and sordid matter which are mingled with them. You must have respect also to the liquor you use to dissolve them in; for Vinegar of the best Wine doth more powerfully pe∣netrate, then that which is of weak and bad Wine.
Other Gums, which are drier, are to be powdred, and are to be mingled with plasters last of all. Metals, as, Aes ustum Chalcitis, Magnes, Bolus Armenius, Sulphur, Auripigmentum, and others, which may be brought to powder, must be mingled last, unless advice be given by long boiling to dull the fierce qualities of them. The like consideration is to be had of Rosin, Pitch, and Turpentine, which must be put in after the Wax, and may not be boiled but very gently, but the fats are min∣gled whilst the other things are boiling. The Litharge is to be boiled with the oil to a just consist∣ence, if we would have the plaster dry without biting. Ce••uss may endure as long boiling, but then the plaster shall not be white, neither will the Litharge of silver make a plaster with so good a color as Litharge of gold. Moreover, this order must be observed in boiling up of plasters: the Litharge must be boiled to his consistence; juices or mucilages are to be boiled away, then add the fats, then the dry Rosin, Wax-Gums, Turpentine, and after them the powders: You shall know the plaster is boiled enough by his consistence,* 1.4 gross, hard, glutinous, and sticking to the fingers, be∣ing cooled in the air, water, or upon a stone. Also you shall know it by his exact mixtion, if that all the things become one m••s•• hard to be broken.