AQUA AMMONIA.

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solution. As a caustic, tlie strong solution of ammonia may be some-times employed with advantage in the bites of rabid animals.

3. The vapour of the solution of ammonia may be inhaled when wewish to make a powerful impression on the nervous system, as in syn-cope, or to prevent an attack of epilepsy. To guard against or relievefainting, ammoniacal inhalations are very powerful and useful; theirinstantaneous operation is frequently astonishing. Pinel says he oncesaw an attack of epilepsy prevented by this means. The patient (awatchmaker) had intimations of the approaching paroxysm from certainfeelings, but he found by inhaling the vapour of ammonia it was fre-quently prevented. In the case of a confirmed epilepsy, which I was inthe habit of watching for some years, I think I have also seen analogousbeneficial effects. I speak doubtfully, because it is so difficult to deter-mine, in most cases, the actual approach of the fit. It is deserving ofespecial notice that ammonia is useful in three conditions of system,which, though produced by very different causes, present analogoussymptoms ; viz., idiopathic epilepsy—the insensibility and convulsions(? epilepsy) produced by loss of blood—and the insensibility and convul-sions (? epilepsy) which poisonous doses of hydrocyanic acid give rise to.

In asphyxia, ammoniacal inhalations have been strongly recommendedby Sage, who says that he produced the apparent death of rabbits byimmersion in water, and recovered them subsequently by the use ofammonia. A case is told us of a man who had been submerged in theSeine for twenty minutes, and who, when taken out of the water, appearedlifeless, yet by the use of ammonia recovered ; and a M. Routier, a sur-geon of Amiens , is said to have restored a patient in the same way.That it may sometimes be of service I can readily believe, but it must beemployed with great caution.

4. Ammonia is given internally as a stimulant and sudorific in a varietyof cases with manifest advantage. In recapitulating these, I must bevery brief.

(«.) In continued fevers which have existed for some time, and whereall violent action has subsided, and the brain does not appear much dis-ordered, ammonia is occasionally of great service. Its diaphoretic actionshould be promoted by diluents and warm clothing. It has an advan-tage over opium—that if it does no good, it is less likely to do harm.

(6.) In intermittent fevers, ammonia is sometimes of advantage givenduring the cold stage to hasten its subsidence.

(c.) In the exanthemata, when the eruption has receded from the skin,and the extremities are cold, ammonia is sometimes of great benefit onaccount of its stimulant and diaphoretic properties. But in many ofthese cases the recession arises from, or is connected with, an inflamma-tory condition of the bronchial membrane, for which the usual treatmentis to be adopted.

(d.) In some inflammatory diseases (especially pneumonia and rheu-matism) where the violence of the vascular action has been reduced byproper evacuations, and where the habit of the patient is unfavourable tothe loss of blood, ammonia has been serviceable.

5. In certain affections of the nervous system, ammonia is frequentlyemployed with the greatest benefit. Thus it has been used to relievethe cerebral disorder of intoxication. In poisoning by those cerebro-spinants commonly termed sedatives, such as foxglove, tobacco, and