feel myself more strong and active, and less sensible of cold. My diet has been much as usual, but my appetite rather increased. I have occasionally taken a little bark to maintain the general tone of the system; and on returning home after each walk, I have found that a few drops of hartshorn in water were refreshing, and prevented thirst during the rest of the day.

"By what I have learnt from very good authority, the exercise I perform is not one-twentieth part of what the Newmarket riders undergo. There is hardly an example of one of those who follow the advice of a skilful physician in their process of wasting, that suffers by it; and the opinion that either their health is injured or their life abridged, is altogether erroneous. Excessive purging is never used now, except when the riders are too lazy to undergo violent exercise, for purging is found by experience to be a much more prejudicial mode of reducing their weight. Sweating by muscular action with an increased quantity of clothing might be recommended not only to rheumatic patients as a safe and easy remedy for their pains; but to persons of both sexes who are troubled with redundant corpulency.

“ "P. S. Since the above was written, I have had leisure to make some further observations which I beg leave to add.

"I am still more convinced that a very profuse and long continued perspiration, promoted by muscular action, is not necessary to the cure of rheumatism, or to the improvement of general health, unless corpulency be one of the evils which is to be removed. Perspiration may be useful as a proof that a very strong action is established in the system, and may in some sort be regarded as the measure of that action; in the same manner as the point of ebullition is referred to as a rough thermometer by those who want very warm water. Of the very much which has been attributed to sensible and insensi

ble perspiration a great deal certainly is true; but may not much also be attributed to the action excited in the system by. those very medicines which are supposed to promote perspiration? Does mercury, independently of the diseases it cures or causes, diminish the quantity of flesh by mere perspiration?

"As an encouragement to those who might be deterred from the use of this remedy by the apprehension that it is too severe for a weak constitution, I add the following table of my weight taken twice or thrice each day, during the time that I was performing six of these sweating walks, (one in every forty-eight hours), undertaken with a view to ascertain whether the quantity of exercise necessary to cure a sciatica, in such a case as mine, is so great as to cause a material loss of flesh in the patient.

"Before I began to weigh I had already walked nine times. It is therefore only by my general appearance that I can say I had not lost flesh by my first walks. Previously to the six walks of which I am going to state the results, I had been obliged to suspend my exercise for fifteen days, as the weather had been extremely bad, and I had an accidental attack of diarrhoea during four days. I weighed night and morning, before and after walking, always in the same clothes, and these as few as possible, and took every precaution against

error.

Experiments on the bark of the Coccoloba Uvifera. By JOHN BOSTOCK, M. D. of Liverpool.

[From the London Medico-Chirurgical Transactions for 1812.] ALTHOUGH Kino has been, for a considerable time, well known as an article of the Materia Medica, there still remains some uncertainty respecting its origin. It is indeed generally supposed, that there are three substances, somewhat different from each other, to which this name is applied. The one which has been the longest known, and is perhaps the most frequently met with, comes from Africa; but we are entirely ignorant from what plant it is derived. A second species is said to be extracted from the Eucalyptus resinifera of New South Wales; while a third variety, which is brought from the West Indies, has by some writers been ascribed to the coccoloba uvifera, and by others to the mahogany.* Having obtained a quantity of the bark of the coccoloba uvifera from a friend in the West Indies, on whose accuracy I could implicitly depend, I embraced the opportunity of examining its properties, and comparing the extract formed from it with the kino usually employed in medicine.

The bark appeared to have been taken from branches of from one to two inches in diameter, and was partially rolled up, much after the manner of the common Peruvian bark. No part of it was more than one-twentieth of an inch in thickness, and some specimens considerably thinner. It was lined with a fine reddish brown cuticle, while the rest of the bark was of a light yellowish brown colour. The external surface was clean, and nearly free from any protuberances, but in many parts it was marked with slight longitudinal furrows. When cut transversely, the external part of the bark, for about one quarter of its thickness, exhibited a coarser texture than the remainder, and could not be reduced to an equally * Duncan's Ed. Disp. 292; Thomson's Lond. Disp. 213; Murray's Mat. Med. 2. 304; Nicholson's Journ. 6. 232.

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fine powder. It had scarcely any smell; when chewed and kept for some time in the mouth, it produced a moderate degree of bitterness and astringency, with a slight mixture of an aromatic flavour.

A portion of the bark reduced to fine powder, from which a little of the coarser part had been separated, was mixed with forty times its weight of water, and kept for an hour at the heat 200°. A light brown fluid was formed, which was filtered while warm. Although at first it was only slightly opake, it became completely muddy upon cooling, and remained so after being kept at rest for some days, but it was rendered nearly clear by filtration. Fourteen successive infusions were made with the same powder, when it appeared that all the matter was removed which water was capable of dissolving. The second infusion, like the first, was opake, but the thirteen remaining infusions were nearly, or quite transparent. By the application of heat the opake infusions were rendered transparent, but they became opake again as they cooled. The opacity was equally produced whether they were exposed to the atmosphere, or entirely excluded from it. After being kept for some time, all the infusions became mouldy, the quantity of mould being of course greater in the earlier ones. The water was found to have dissolved 42 of the powder; the residue was of a redder colour, and of a more spongy texture than before the experiment. The infusion seemed to retain its transparency until all the water was evaporated; the extract was hard and brittle, and of a very deep reddish brown colour. It was softened by heat, and reduced to a half melted state. From what was observed during the evaporation of the infusion, it seems that water has the power of retaining in solution almost an indefinite quantity of the extract, although, when heated with the bark, it will not originally take up more than one-sixtieth of its weight of soluble matter.

When the coccoloba bark was added to water, and no heat applied, the effect was considerably less; a transparent light brown fluid was produced, after remaining several weeks in