DRUGS AND THEIR DOSES. 93 



applied, muriatic acid acts as a caustic and antiseptic, and may be usefully 

 applied lightly to foul unhealthy sores. 



Mustard Poultice.— To make a mustard poultice : mix with it equal 

 parts or less, according to the stimulation of the part sought to be affected, 

 of linseed meal, and mix them with cold water to the required consistence. 



Myrrh, is a gum-resin, which — by name at least, is familiar to most 

 people. It is an Eastern product, long known, as is proved by the very 

 frequent reference to it in the Bible. The best myrrh is imported to us 

 from Turkey, and comes in small, irregular roundish pieces, called tears 

 of a reddish-yellow colour, and possessing, to most people, an agreeable, 

 although peculiar odour. It is principally used in form of tincture— that is 

 in solution in spirit and in conjunction with other gums and resins, a good 

 form for which will be found under " Aloes." It is very useful as an 

 application to cuts, for the spirit acts as a styptic, and when it has 

 evaporated it leaves a protective coating of the gum deposited on the 

 surface of the wound. It is also an excellent stimulant to all indolent, 

 unhealthy sores of an ulcerous character, correcting their fcetidness, and 

 inuicing healthy granulation. 



Nightshade, Deadly.— See Belladonna. 



Nitrate of Silver.— See Silver, Nitrate of. 



Nitre.— See Potash. 



Nitric Acid, often called aqua fortis, although aqua fortis of the shops 

 is a diluted form of nitric acid.— This is a powerful caustic, quickly destroy- 

 ing animal tissue, and is valuable as an application to all fungoid growths 

 and excrescences. It is, therefore, useful in canker of the foot, &c , and is 

 a destroyer of warts where it can be safely applied, but its great fluidity 

 enjoins that it must be skilfully used, otherwise it spreads on to and 

 destroys surrounding healthy tissue. To avoid this it is often used mixed 

 with flowers of sulphur into a paste. A mixture of it with muriatic acid, 

 known as nitro-muriatic acid, is given internally as a tonic and astringent 

 in doses of one drachm largely diluted with water. 



Nux Vomica.— The seeds of the poison-nut tree from which strychnine 

 is made. See Strychnine. 



Oak Bark and Oak Galls, much more used for cattle than horses 

 both are astringents, and owe that quality to the gallic acid or tannic acid 

 which they contain, and these can be used with more precision than the 

 crude bark and galls from which they are obtained. 



Oils are animal or vegetable, according to the source from which they 

 are obtained, and they are either fixed or fat oils, or volatile, or essential 

 oils, but the old farriers, like too many modern farmers, use the word as a 

 sort of abracadabra referring to the utterly absurd mixtures they call their 

 " iles" with the pride of ignorance in the possession of a supposed grand 

 secret. Who has not met with the "knowing horsey man" who has a 

 recipe for oils that will cure everything, from a simple cut to a break 

 down. The wonder is not so much that these people deceive themselves, 

 but that in these enlightened days they are still able to impose on in- 



