TREATMENT OF DISEASES OF THE HORSE. 475 



branclies of various trees. It is employed in the form of ^ mucilage, 

 inade?bY dissolving it in water, in tlie proportion of one part of the gum 

 o th;ee or fom- of water. Various insoluble powders may be tbus sus- 

 pended, or oils rendered miscible, or emulsions formed. Emulsions com- 

 posed of gum arable are supposed to be usefu m urmary aflfections. 

 ^ AciDTO AcBTiCTO, Acetic Acid, YiNEG.B.-Acetic, o^ PF-«l^g^^°^^,.^«^^^^ 

 is obtained by tbe destructive distillation of wood It is about six times 

 i strong as ordinary vinegar, and is seldom used except m this diluted 

 form Vineo-aris obtained by wbat is called the acetous fermentation, 

 excited in a laccharine solution. Everyone is familiar with the Properties 

 of ^^egar, it has been employed for sprains and bruises, and equal parts 

 of cold vii^egar and boihng water wiU form a good fomentation. As an 

 hitemal remedy, vinegar is^arely given, nor has it, except m large doses, 

 anv considerable medicinal power. 



AciDUM Aeseniosum, ARSENic.-Were it not that some practitioners coiv 

 tinue to use it as a tonic, in doses of from five to ten gi-ams daily and 

 others employ it to core out old ulcers, we would not include it m our list 

 for we haie Httle faith in it. There are better and safer tomes and far 

 better and safer caustics. The method of detecting the presence of arsenic, 

 in cases of poisoning, will be found described at page 600 



AciDUM MuRiATicmi, or Htdrochlokic Acid: Spirit of Salt.— This acid 

 is obtained by distiHing a mixture of sulphuric acid and common salt and 

 water The acid is generated in the form of gas, and is conveii^ed into a 

 liquid by admixtui-e with water in the receiver. In this state when pure 

 it is colourless, but the ordinary acid met mth in commerce is of a yellowish 

 colour When exposed to the air, it emits suifocating fumes, and^ from 

 its great afl&nity for water, should be always kept m well-stopped bottles 

 it is chiefly employed as a caustic in ulcers a,nd other ill- conditioned 

 wounds. When Spphed to any living part, a change of colour is perceived 

 the parts becoming blanched. For canker, wounds m the foot not 

 attended by healthy action, and for every case where the superficial ap- 

 pi cation of a caustic is needed, this acid will be found especially valuable. 

 It has also been given in a diluted form as a solvent of calculi m the 

 kidnevs and bladder. . , . , , 



AciDUM NiTRicuM : I^iTRic AciD, Aquafortis. -This acid IS obtamed by 

 distilling together a mixture of sulphuric acid and nitrate of potassa. _ it 

 is a pak straw-coloured fluid, with a pungent acrid smeU, and possessmg 

 very corrosive properties. Aquafortis is a diluted form of this acid. 

 Nitric acid is a valuable external appHcation. It is both a caustic and an 

 antiseptic. It destroys fungoid excrescences. A pledget of tow should 

 be dipped in the acid, and then firmly pressed on the cankerous surface 

 Every part with which the acid has come into contact wiU be deadened 

 and slough off, and healthy granulations will spring up. _ 



AciDuS Htdrocyanicum : Prussic Acid.— It is prepared by mixing to- 

 gether cyanide of silver, hydrochloric acid, and water In this state 

 it will be found a colourless Hquid, with a pungent bitier taste, and a 

 peculiar odour somewhat resembhng bitter almonds. The hydrocyanic of 

 the London Pharmacopoeia contains about two per cent, ot acid, while 

 Scheele's acid, which is more generally used in veterinary practice, con- 

 tains from foui^ to five per cent. In a concentrated _ state, it is truly a 

 deadly poison ; a few drops of it ^vill kdl a large animal. In a diluted 

 fonn ^it^s a powerM sedative. In doses of half a drachm to a drachm, 

 laro-ely diluted, it abates both pulmonary and gastiic irritation, it has 

 also been used with good effect in the form of enema m cases of tetanus. 

 It may also be given by the mouth in the same disease. Nothing is more 

 likely to tranquillise the general excitement of the nervous system. The 



