MEDICINES.] 



THE HORSE, AND 



[medicines. 



soluble in alcohol, usually affording much soot 

 by their combustion. They are likewise solu- 

 ble in oils, but not at all in water, and are 

 more or less acted on by the alkalies. All the 

 resins appear to be nothing more than volatile 

 oils, rendered concrete by their combination 

 with oxygen. Analysed by MM. Gay Lussac 

 and Thenard, resin was found to consist of 



Carbon, . .75-944 



Hydrogen . . 10-719 ) Water, 15-156. 



Oxygen . . 13-373 j Hydrogen in excess, 8-9- 

 The resin of fir is known by the name of 

 rosin. Its properties are well known. Its 

 specific gravity is 1072. It melts readily; 

 burns with a yellow light, throwing ofi:' much 

 smoke. Eesin is insoluble in water, either hot 

 or cold, but very soluble in alcohol. 



The plant which yields euphorbium is peren- 

 nial, succulent, and shrubby. It is obtained 

 by making incisions in the branches, from 

 which a lartious gum exudes, and concretes 

 into drops. 



Medicinal Uses. — Stimulant. Eubefacient. 

 It is used externally, entering into the com- 

 pound unguentum cantharides. Internally it 

 is given as a diuretic, in doses of from five to 

 six drachms, made into a ball, with soft soap. 

 A preference, however, is given to the common 

 liquid turpentine. 



Fekei Sulphas — Sulphate of Iron — Copperas. 



Copperas is the green salt sulphate of iron ; 

 and the blue salt sulphate of copper is also 

 sometimes called copperas. 



Take of Iron (by weight) 

 „ Sulphuric Acid . 

 „ "\A'ater . 



8 oz. 

 8 „ 

 4 „ 



Mix the sulphuric acid with the water, in a 

 glass retort, and to tliis add the iron in the 

 form of filings. When bubbles cease to escape, 

 filter the solution through paper, and evapo- 

 rate over a slow fire, so that, as it cools, crys- 

 tals may form. Having poured off" the super- 

 natant fluid, dry the crystals upon bibulous 

 paper. 



Gentiana — Gentian. 

 Of this plant there are many species. The 

 most remarkable are the lutea, or common 

 gentian, the root of which is an excellent 

 stomachic bitter ; and the lesser centaury. 

 354 



Decomposition. — Water consists of oxygen 

 and hydrogen, and a portion of it is decom- 

 posed by the action of the sulphuric acid and 

 iron. Its oxygen unites to iron, converting it 

 into an oxide of iron; before which the sul- 

 phuric acid will not act upon it, whilst its 

 hydrogen being set free, escapes in the form 

 of gas. The oxide of iron is then dissolved 

 by the sulphuric acid, and sulphate of iron is 

 formed. 



Jiledicinal Uses. — Tonic ; combined with 

 ginger. — Carbonate of Iron is a mild tonic 

 given in doses of from two to four drachms. — 

 As a stomachic, and a tonic, gentian holds 

 the highest place in veterinary practice. 

 Four drachms of it, two of camomile, one 

 of ginger, and one of carbonate of iron, 

 make an admirable tonic ball. An applica- 

 tion of an infusion of gentian to putrid ulcers 

 is one of the best. 



Gltcyeehiz^ Eadix — Zigfuoriee Boot. 



The glycyrrliiza, or common liquorice sJirub, 

 has a long, thick, creeping root, striking several 

 feet deep into the ground. It is an annual, with 

 an upright, firm, herbaceous stalk, three or four 

 feet high, garnished with winged leaves, of four 

 or five pair of oval lobes, terminated by an odd 

 one ; and from the axillas, erect spikes of pale 

 blue flowers in July, are succeeded by short, 

 smooth pods. The root of this plant is the 

 useful part, being replete with a sweet, bal- 

 samic, pectoral juice, which is either extracted, 

 or the wood sold in substance. It is much 

 used in all compositions for coughs, and disor- 

 ders of the stomach ; but by far the greatest 

 quantity is used by brewers. The common 

 liquorice is cultivated in most countries of 

 Europe, for the sake of its root ; but in Spain 

 and Italy, and particularly in Sicily and Cala- 

 bria, it makes a considerable article of com- 

 merce with this country. Liquorice also 

 grows in great abundance in the Levant ; and 

 vast quantities of it are consumed there, in 

 making a decoction which is drunk cold in the 

 summer, in the manner of sherbet. 



To prepare liquorice, the roots are boiled a 

 long time in water, till the fluid acquires a 

 deep yellow tincture ; and the water at length 

 evaporated till the remains assume consis- 

 tencv, when they are formed into sticks, which 

 are packed up with bay leaves, in the same 



