22 MATERIA MEDICA. 



that is used in veterinary practice, — an ea- 

 sential oil, of a dark colour, and very disa- 

 greeable odour, — which is employed as an 

 embrocation in strains, bruises, &c. gene- 

 rally mixed with other oil, such as oil of 

 elder, turpentine, &c. It is given internally 

 as an antispasmodic, in doses from two 

 drams to half an ounce, i? or medical pur- 

 poses this essential oil is rectified, whereby it 

 becomesof alighter colour, and loses in some 

 degree its unpleasant smell ; but it does 

 not appear to be rendered more efficacious. 

 There is a salt of amber kept in the shop^, 

 procured from amber b}^ sublimation, but 

 it is never used in veterinary practice. 



AMMONIA. This is the modern term 

 for what was named volatile alkali, and i^s 

 procured either from bones or sal ammoniac. 

 It is kept in the shops, both in a solid and 

 a liquid form. Strictly speaking, pure am- 

 monia exists onl}^ in the form oi gas, or air; 

 but water will absorb a considerable quantity 

 of this air, and when saturated with it be- 

 comes a violent stimulant, capable of in- 

 flaming and even blistering the skin. This 

 is termed xvater of pure ammonia, or strong 

 spirit of sal aimnoniac, and is extremely 



