This is a former officinal of the Edinburgh College, intended to afford the means of obtaining, at pleasure, a powerful rubefactive, vesicatory, or even caustic effect from ammonia, or a mild rubefaction only. it consists of five measures of stronger solution of ammonia (see page 755), two of tincture of camphor, and one of spirit of rosemary. A weaker preparation, directed by the College, was made by adding three parts of tincture of camphor and two of spirit of rosemary. These are mere dilutions of the stronger solution of ammonia; the additions having no other special effect than to modify the odour. The stronger preparation is used for blistering or cauterization (see page 755). The weaker may be employed as a powerful and very prompt rubefacient. Even this will also vesicate or cauterize if long applied. But, used as a lotion, and withdrawn at the moment that it has sufficiently reddened the skin, it may be employed in cases where a very speedy and efficient impression is required; as in violent internal spasms, intense neuralgic pains, or great general prostration. in violent cases of spinal irritation, it may be applied along the spine with advantage.