* See Dr. Prout, op. cit.; Sir B. Brodie on Dis. of the Urinary Organs; and an able paper by Mr. Rowe, Dub. Med. Journ., vol. xviii. p. 277.

Garrod, Ess. Mat. Med., p. 103.

Op. cit.

§ Garrod, Med. Times and Gaz., Feb. 6, 1864.

|| Analysis of the Blood and Urine, p. 137.

¶ Guy's Hospital Reports, 1861, vol. vii.

2803. As alteratives in Gout, Rheumatism, Scrofula, Phthisis, Bronchocele, &c., the Alkalies prove useful, partly by their property of liquefying or attenuating the blood and the various secretions, and partly by correcting any abnormal acidity which may be present in the stomach or in the circulating fluid. In the former of these ways they prove useful in the advanced stages of Pneumonia and Bronchitis, when the expectoration is thick and viscid. As a liquefacient remedy, the Liq. PotassAe is perhaps the best form which can be employed. The carbonated Alkalies are generally less efficacious.

2894. Alkalies are also employed as a means of supplying the blood with those alkaline principles which are excreted from the system in the form of profuse discharges, &c. It is well known that a large portion of the saline particles of the blood are held in solution or suspension in the serum of the blood; and consequently, when, from any morbid action, a great amount of fluid is abstracted from the system, whether in the profuse perspirations of Phthisis, or in the copious dejections of Cholera, the discharge contains so large a quantity of salines, as to incapacitate the vital powers from performing their functions in a normal manner. In order to remedy this mischief, Alkalies are administered, and to prove effectual they should be given in small doses, largely diluted.

2895. The well-known chemical affinity of Alkalies for fat has led to their employment in the treatment of Obesity. In this capacity, they have been found most serviceable by Flemyng, Chambers, and others.

For the special action of each of the Alkalies, the reader is referred to the articles on each in the former part of the work.

2896. Alteratives are medicines which gradually correct the deranged or morbid condition of an organ, or of the constitution, and restore it to its healthy or normal state, without evidencing their action by an immediate or sensible evacuation. There are few medicines which may be regarded as solely alterative, but there is scarcely a single drug, however violent in its operation in large doses, which may not, by the proper regulation of the dose, or by its mode of preparation, be converted into an alterative. Mercury, Arsenic, and Antimony may be taken as examples of this fact.

Alteratives are especially applicable to chronic diseases and passive derangements; those of an acute character requiring a more active class of remedies. In all chronic diseases, it may be laid down as a general rule, that nothing is to be gained, and that much permanent mischief may result, from the employment of violent remedies. When medicines are given with a view to their operating as alteratives, they generally require to be administered in small doses, and to be persevered in for a lengthened period, namely, for weeks, and perhaps months; the practitioner being satisfied with witnessing, at considerable intervals, an improvement, however small, in the state of the patient. A careful regulation of the diet, and a strict attention to personal hygiene, are indispensable auxiliaries to an alterative course of medicine. Without these, remedies can be of little avail.

2897. Anaphrodisiacs are medicines which subdue and destroy sensual habits and feelings. They do not demand any lengthened notice; indeed, their existence as a class has been denied by some writers; there, however, appears but little doubt that certain medicines do act in this manner. At the head of these may be placed Bromide of Potassium, Digitaline, Lupulin, and Camphor. The extracts of Lettuce and Hemlock are also reputed to have this effect; and Tartar Emetic, by its depressing action on the vascular system generally, and the saline purgatives, may be regarded as belonging to this class. The diseases in which they are indicated are Nymphomania and Spermatorrhoea.

289S. AnAesthetics are agents which prevent pain, and diminish sensibility. They may be divided into two classes: - 1, those which, either given internally, or applied locally to the part, effect these objects; as Opium, Aconite, Belladonna, &c, all of which are more properly considered under the heads of Narcotics, Anodynes, or Sedatives; and Ice, or congelation, whose anaesthetic power is sui generis: 2, those, the vapours of which induce more or less complete insensibility, and thus allow the performance of surgical and other operations, without pain or consciousness on the part of the patient. To the second class, the following observations principally refer. The chief articles of this class are, - 1, Chloroform; 2, Ether; 3, Hydrobromic Ether; 4, Coal Gas; 5, Chloride of Olefiant Gas, or Dutch Liquid; 6, Bisulphuret of Carbon; 7, Aldehyde; 8, Amylene; 9, Acetone. There are also others of minor importance.

2899. Although this class of remedies has only, within the last few years, been brought into general use in European practice, it appears probable, from a Chinese work now in the National Library at Paris, that anAesthetic agents during surgical operations were in use among the Chinese above 1600 years ago.*

The properties common to all the articles of this class art

* See Coroptes Rendus, Jan. 29,1850.

1, volatility: 2, the presence of Carbon; 3, solubility in the serum of the blood.

Their mode of action has been supposed to be, primarily, upon the nerves; secondarily, upon the respiration, the heart, and the circulation. But there is no doubt that these agents enter into the blood. Under the influence of Chloroform and Ether the amount of carbonic acid excreted in respiration is diminished, showing that the processes of oxidation in the body are interfered with. Dr. Snow believed that it was the special property of Chloroform and other volatile narcotic fluids to arrest oxidation. He observed that the venous blood of patients under the influence of Chloroform was less dark in colour than in the normal state.

They all act, more or less, in the first instance, as stimulants. With Chloroform, this stimulus is comparatively slight; with Ether, Aldehyde, &c., it is more considerable.

Their action may be local. When applied to a limited portion of the body, that portion is rendered anaesthetic.

chloroform is the most powerful, but not the safest of this class. Ether produces much excitement, and leaves headache; but is not so liable as Chloroform and some others to produce fatal consequences. A mixture of Ether and Chloroform with Alcohol, as recommended by the Committee of the Royal Medico-Chirurgical Society, is perhaps the best anaesthetic that can be employed. (See Chloroform, part i.)

Their action is far from uniform. The same dose does not produce the same effects, even in the same individual at different periods.

The young bear proportionably larger doses than adults.

Hysterical females are peculiarly susceptible to their action. The danger is proportioned to the concentration of the vapour. It is, therefore, necessary that the air should be allowed to mix freely with it.

Some of these agents, externally applied, do not produce any irritation of the skin, e.g., Ether and Aldehyde; whilst others, as Chloroform and Dutch Liquid, cause a sense of burning, and, if applied for a sufficient length of time, vesication. The energy of local anaesthetic power is in an inverse ratio to volatility. (M. Aran.)

Measures to be adopted in case of an over-dose. 1, Artificial Respiration by the Marshall Hall or Sylvester methods, or by mouth to mouth insufflation; 2, Galvanism. In all cases the patient should be exposed to a cool and pure current of air, the mouth should be opened, and the tongue drawn forward. In slight cases Ammonia to the nostrils and the cold douche may be sufficient to restore the patient.

The therapeutic applications of this class are considered at length in the article Chloroform, part i.