MIDICINE8.] 



MODEKN VETEliiNAlii' i'KACTiCE. 



[Mi:uiciKKa. 



tract it unaltcrod from the k'uvoa of trees, nnd 

 other vegetable subslaiiees that contain it. 

 Several plants contain wax, in such abundance, 

 ns to niako it worth while to extract it from 

 them. 



Mt'iUcinal Uscs.-ln charges, and some 

 plasters, tho yellow soap is used to make them 

 less brittle. In small doses (and with great 

 attention), from one scruplo to ono drachm, 

 frequently giving it, will produce a sedative 

 eflect : but if this clVect be not narrowly 

 watched, or if the dose bo increased from one 

 drachm, nausea will be produced, and violent 

 irritation. As it is a powerfuel diuretic cathar- 

 tic, it must be used with extreme caution. 

 Externally it is combined with oil. It may, 

 however, be used with advantage in allections 

 of the skin, either in the form of decoction 

 or ointment. We must repeat that, without 

 the utmost care, it is a dangerous drug. 



The Black Ilellehore is used mostly as an 

 external application, and has a strong, stimu- 

 lating power. It has been resorted to with 

 success in fistulous affections of the poll and 

 withers. Professor Morton observes, " that 

 an ointment, formed of either the white or 

 black hellebore, in the proportion of one part 

 of the powder to eight parts of larch, will be 

 found exceedingly active for the dressing of 

 rowels and setons." 



Zixci OxTDUii — Oxide of Zinc. 



In chemistry and mineralogy, zinc was a 

 metal unknown to the ancients, though they 

 were acquainted with calamine, one of its ores, 

 and the eflect which this had iu converting 

 copper into brass. It is of a white colour, with 

 a shade of blue ; in a fresh fracture it is pos- 

 sessed of considerable lustre. It is hard, and 

 not easily cut with a knife. The specific 

 gravity is nearly 7'2. Its ores are calamine 

 and blende. — Calamine is an oxide, frequently 

 with a portion of carbonic acid ; blende is a 

 sulphuret, containing also some iron, and other 

 extraneous matters. 



Zinc is melted by a moderate heat ; and the 

 fused mass, on cooling, forms regular crys- 

 tals. Though scarcely altered by exposure to 

 the air at a low temperature, yet it is rapidly 

 oxidised by one amounting to ignition. "When 

 kept in a degree of heat barely sufllcieut for 

 its fusion, it becomes covered with a grey 

 3 a 



oxide. But when thrown into a crucible, or 

 deep earthen pot, heated to whitenesH, it Hud- 

 denly inflames, burns with a beautilul whito 

 flame, and a whito and light oxido hublimcs, 

 having a considerable resemblanco to carded 

 wool. 



Medicinal Z'ses. — Tonic ; but in tho impure 

 state, under the name of Calamine Powder, 

 used as an ointment, known as "Turner's 

 Cerate," it is invaluable. Tiiis ointment has 

 been distinguished as "The llealing Oint- 

 ment," and is composed of five parts of lard 

 and one of resin, melted together. AT lieu 

 these begin to cool, two parts of the cala- 

 mine, reduced to an impalpable powder, are 

 stirred in. On cracked heels, and superficial 

 sores, calamine is sometimes advantageously 

 sprinkled. 



ZiNCi Sulphas - 



-Sulphate of Zinc— White 

 Vitriol. 



Take of Zinc, in small pieces . • 4 oz. 

 ,, Sulphuric Acid (byweight) G „ 

 „ Distilled Water ... 4 pints. 



Mix them in a glass vessel ; and the eflLcrves- 

 cence having ceased, filter the solution through 

 paper, then boil it till a pellicle appears. Set 

 it by, that crystals may form. 



decomposition. — The same process acts here 

 as in the preparations of the sulphate of iron 

 and copper. The oxygen of the water unites 

 to the zinc, converting it into an oxide of zinc, 

 which is dissolved by the sulphuric acid form- 

 ing sulphate of zinc ; whilst the hydrogen of 

 the water assumes the elastic form, and escapes. 



Medicinal fTscs.— Tonic internally; stimu- 

 lant externally. As a tonic, it is given in 

 doses from one drachm to half-an-ounce ; but 

 it is now rarely used at the College. It is 

 used externally to promote healthy granula- 

 tions ; and may be applied either in the form of 

 solution or ointment. 



ZiNGiBEEis Eadii — Ginger Root. 

 This plant is a native of the East Indies, 

 but is now cultivated in the West Indies, to 

 very great advantage. Our finest quality 

 comes from Jamaica. The root is dug up after 

 the herbaceous part of the plant is withered 

 in January, and dried in the sun. There are 

 many sorts in the market, but they all possess 

 similar properties, dift'ering slightly in strength. 



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