It is always extremely difficult to prove the prophylactic power of any agent, as it is impossible to say whether an individual who has recourse to it, and escapes the invasion of the disease against which it is supposed to operate, would not equally have escaped, if he had not employed these means. With respect to Quinine as a prophylactic agent against fever, I have on several occasions observed, that of a number of persons exposed to the same malarious influence, those who made it a daily practice to take two or three grains of Quinine, have escaped fever; whilst those who either neglected, or laughed at the reputed preventive, were attacked by it; at the same time it must be admitted, that in both classes some exceptions presented themselves. How far the mind may exercise an influence in these cases, it is impossible to determine; but it has always appeared to me, that Quinine does exercise a considerable influence in preventing the invasion of fever. Dr. Copland* evidently inclines to the same opinion, and recommends the following pills: -

2322 The Powers Of Quinine At A Prophylactic Of Fe 197Camphor. j., QuinAe; Sulph. 3ss., Pil. Galb. Co. 3j., Pulv. Capsici gr. xvj., Balsam. Canad. q. s. ft. pil. xxxvj., cap. ij. - iij. hora somni. I have, however, generally contented myself with ordering two or three grains of Quinine to be taken in solution, either immediately before, or with a cup of hot coffee, the first thing in the morning.

2323. In Remittent Fevers, Quinine is a remedy of the highest value, but its exhibition requires more caution and discrimination than in simple Intermittents. The plan first propounded, in 1847, by Mr. Hare. of the Bengal Medical Service, of administering Quinine in repeated scruple doses at all stages of the fever, even during the height of the exacerbations, has attracted much notice, and has had able advocates; but it has not met with favour with the profession generally. Dr. Morehcad considers that the tendency of the system is to favour superficial clinical observation. Sir Ranald Martin§; expresses himself as opposed to it, and Dr. Kenneth Mackinnon|| considers that Quinine is best given in small doses during the remissions only; diaphoretics, purgatives, and other depletory measures, being used during the paroxysm. My own experience coincides, on the whole, with that of the latter practitioner, though I believe that the remedy may be given at an earlier period and in larger doses than he prescribed. Where, observes Sir R. Martin,* with a state of general plethora, visceral congestions remain unsubdued or only partially removed, the secretions being scanty and depraved, with the pulse full and hard, and the skin dry, and hot, the time for the exhibition of Bark has not yet arrived. But when venous congestions have been overcome by previous depletory means, when the pulse has been reduced in force and frequency, when the secretions are in free action and the skin relaxed, we may be sure of establishing the anti-periodic influence of Quinine with the best effect, and without risk of producing injury. It then becomes a sovereign remedy, and must be given in full doses, so as speedily to establish its influence. The amount and frequency of the dose will depend on the nature of the fever: where the paroxysms are violent, or where the sufferer is in a malarious locality, the dose should be large and often repeated. It is better to exhibit the Quinine in five-grain doses often repeated, than to give scruple doses as recommended by some writers. Full details of Dr. Hare's treatment have recently been published by that gentleman. and also by Dr. Ewart.

* Dict Pract. Med., vol. i. p. 921.

On Fever and Dysentery, Delhi, 8vo, 1847.

Diseases in India, &c, 2nd Ed., p. 146.

§ Tropical Diseases, Ac., Ed. 1861, p. 338. || Diseases of Bengal, &c., p. 207.

2324. In Bilious, Remittent, or Yellow Fever, the abortive treatment, as it has been termed, which consists of the administration of one large dose (grs. xxx. - xl.) of Quinine with Morphia or Opium at the outset of the disease, was introduced in 1837 by Dr. Thevenot, of Guadaloupe, and met with supporters in Dr. Blair, of Demerara, Dr. Harrison, of New Orleans, &c. Notwithstanding the lavish praises of these physicians, it failed in the hands of Drs. Van Buren, Fenner, and others. Dr. Stille § sums up the evidence pro and con in the following words: - 1. That Quinia is not a specific for Yellow Fever as it is for periodical fevers of every type. 2. That, in mild cases which would probably recover under good nursing and the expectant treatment, the medicine may sometimes hasten recovery. 3. That, on the whole, the results depending upon Quinia are no better, if indeed they are as good as those of the treatment of symptoms sanctioned by general experience. This is perhaps a little too low an estimate of the powers of the drug: some of the evidence in favour of its powers was very strong.

* Op. cit., p. 338. Medical Times and Gazette, Nov. 1864.

Indian Annals of Med. Science, vol. vii. p. 267. § Therapeutics, 1860, vol. i. p. 517.