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Infusum Sennae simplex, P. L. 1787. Infusum Sennae commune, P. L. 1745. Infusum Sennae, Ρ. L. I 20.
Tahe of Senna Leaves, an ounce and half. Ginger Root sticed, a drachm. Boiling Water, a Pint. Macerate sor an hour in a covered Vesset, and strain the liquor.
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I AE term Mucilage, is employed in Pharmacy, to designate certain aqueous solutions Which are very thicla and adhesive. In Chemistry, it is applied to a union of gum With water,and, by some, is conceived to belong to a peculiar principiedistinct Dom gum. The former mucilage of Quince seed, as being much thinner than the others, has been transferreuto decoctions. The mucilage of Tragacanth is omitted, aspossessing no advantage oVer that of Acacia gum, and as bellagmore dissicultly solubie, very thich, and apt to become lumpyon dilution.
added, untii it incorporales into a mucilage.
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This mucilage is prepared by trituration of thepowderedom mitti bolling water only. The gum is also solubie in vegetableacids; insolubie in athohol, and precipitaled by it; insolubie also in ether and otis, but trituraled with the lalter, either When it is naturalty present in the vegetabies containing them,or is added artificially, it divides and suspends their particle in mater, forming a White opaque mass, formerly called Emuiassen. Some of the metallic salts of mercury, iron, and antimony appear to be changed by it, and there re inould bo exhibited, in mixtures containing it, With some caution. This mucilage is mostly impure stom the presence of extraneous matters which have adhered to the gum, and such canonly be separated by pressing it through a coarse cloth.
Tahe of Stareli, three drachmS. Water, a Pint. Rub the starch, gradually adding the water toiit, then bolliuntii it incorporales into a muCilago.
Starch rubs with cold Water into a White opaque fluid, and, when healed, forms a gelatinous liquor, Which may be diffused through more botling Water, but precipitates aster
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standing. It is insolubie in ether or alcohol. Thomson considers it as a characteristic of this vegetable matter, thatit is solubie in infusion os galis at 120'; precipitates as it coois, and may again be dissolved by an increase of temperature : this seems to be the result os a combination belweenstarch and tannin.
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broad shallow disti by means of a Water buth, untii they have acquired a Consi Stela CC pro PCrsor mul ing pilis, and to variis the end of the in spissation constantly stir them With a
Sprinkle tapon ali the extracis a smaliquantity of recti fled spirit.
The generic term Extraci is used pharmaceuticalty in an extensive sense, and includes ali those preparations Domvegetabies Whicli are separabie by the agency of Various liquids, and afterwarcis obtained Dom sucti solutions, in asotid state, by evaporation of the menstruum: it also includes those substances which are held in solution by the naturali uices of Desti planis, as weli as those to which some me struum is added at the time os preparation. NoW, such solubie matters are Various and mostly complicated, so that chemicat accuracy is not to be looked sor in the applicationos the term. Chemisis, however, have affxed this name toone peculiar modification os vegetable matteri Whicli has Deen called Extractive, or Extraci, or Extractive Principi
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and as this Arms one constituent part of common Extracis, and possesses certain characters, it Will be proper to mention suchos them as may influence iis pharmaceutical relations. The Extractive Principie has a strong taste, differing in different planis: it is solubie in Water, and iis solution speedij runs into a state of putrefaction, by Whicli it is destroyed. Repeated evaporations and solutions render it at last insolubie, in consequence of iis combination With oxygen Dom the atmosphere. It is solubie in alcohol, but insolubie in ether. It unites with alumine, and is boiled With neutral salis thereos, precipitates them. It precipitates With strong acidf, and with the Oxyds frona solutions of most metallic salis, especialty muriata of tin. It readily unites With aikalies, and forms compoundsmith them Whicli are solubie in Water. No pari, hoWever, of this subject has been hitherio sussiciently examined. The generat rules for their preparation, Whicli are given in
the texi, require minute and accurate attention, more particularly in the immediate evaporation of the solution, Whether prepared by expression or decoction, in the manneras weli as the degree of heat by Whicli it is performed, and the promotion of it by changing the sursace by constant stirring when the liquor begins to thichen, and even by directing a strong current of air over iis furface, is it can conveniently be done. It is impossibie to regulate the temperature over a naked fire, or is it be used to prevent the extractsrom burning , the use of a mater bath is theresere absolutelynecessa , and not to be dispensed With, and the beauty and precision of extracts so prepared will demonstrate their superiority. I have on this account not judged ii superfluous togive an oviline of a modification of the common tin faucepanwhich I devised for the use of St. Bartholomew's Hospital,
and which, Bom iis simplicity and facility os application,
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mployed nahed stres for this purpose. For this mode os preparation, Volatile and aromatic substances are unsit, and the clarification or defaecation of the liquor is, in every instance, improper. The spirit is added to the soster extracisto preserve them Dom moulding. The omissions froin theformer Pharmacopoeia are, Extractum Cacuminis, Genistae, Rutae, Sabinae, Cascarillae, Sennae, and Succus Baccae Sambuci spissatus. The additions to the present are, Extractum Aconiti, Belladonnae, Aloes, Colocynthidis, Humuli, Hyoscyami, opii, Rhei, Sarsaparillae, Taraxaci. The consistence of extracis is important ; it should be suci as to retain the round form os a pili Without any addition os poWder. They areusualty too sost, and the temptation is considerable to those who prepare them for sale in a large Way, not to evaporate them to the proper consistence.
Tahe o Aconite Leaves fresti, a POUnd. Bruise them in a stone mortar, sprint lingon a litile Water: then press out the juice, and , Without any separation of the sediment, evaporate it to a proper ConsiSten Ce.
is, and the Extracta Belladonnae, Conii, and Hyoscyami Would, in the former Pharmacopoeia, have been called
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. 21 inspissated Juices, and are prepared according to one common process. Their texture is sirst destroyed by bruising, thejuice is then expressed, and reduced by evaporation to a properconsistence. They ali possess narcotic properties, and require caution and attention in their exhibition, though uponthe whole, and Dom tolerably large eXperienee, I am convinced that in common practice they are under-dosed ratherthan the contrary, and that to this circumstance is to be a
cribed their frequent fallure of effeci. Different modes of preparing these extracis have been used, ali of whicli mere considered when the present directions Were adopted. Somepour off the clear liquor fioin the green seculent matterwhicli subsides when the juice is heated, and evaporating it by itself, mix the two together aster the liquor has acquired the consistence of syrup. Others carry on the evaporationos the whole only untii it becomes of the thicliness of syrup, and then give it a pitular consistence, by the addition ApoWder of the leaves.
Macerate sor three days in a gentie heat, then Stra in the solution, and set it by that