its jaws, but by twisting its own neck twice round that of the water-fnake, pulled it back from the ditch. To prevent a defeat,, the latter took hold likewife of a stalk on the bank, and by the acquifition of that point of refiftance became a match for its fierce, antagonist. Strange was this to behold; two great fnakes ftrongly adhering to the ground, mutually faftened together by means of the writhings which lafhed them to each other, and stretched at their full length, they pulled, but pulled in vain; and in the moments of greatest exertion, that part of their bodies which was entwined feemed extremely fmall, while the reft appeared inflated, and now and then convulfed with ftrong undu lations, rapidly following each other. Their eyes feemed on fire, and ready to start out of their heads. At one time the conflict feemed decided; the water-fnake bent itself into two great folds, and by that operation rendered the other more than commonly out-ftretched; the next minute the new ftruggles of the black one

gained an unexpected fuperiority; it acquired two great folds likewife, which neceffarily extended the body of its adverfary in proportion as it had contracted its own. These efforts were alternate; victory feemed doubtful, inclining fometimes to the one fide and fometimes to the other, until at last the stalk to which the black fnake faftened, fuddenly gave way, and in confequence of this accident they both plunged into the ditch. The water did not extinguish their vindictive rage; for by their agitations I could trace, though not diftinguifh their mutual attacks. They foon re-appeared on the furface twifted together, as in their first onfet; but the black snake seemed to retain its wonted fuperiority, for its head was exactly fixed above that of the other, which it inceflantly preffed down under the water until it was ftifled, and funk. The victor no fooner perceived its enemy incapable of far ther refiftance, than abandoning it to the current, it returned on fhore and disappeared,

Some Account of the Chemical and Pharmaceutical Hiftory of the Red Peruvian Bark, in order to fhew its Efficacy as a Part of the Materia Medica to be fuperior to that of the common Bark Extracted from Obfervations on the Superior Efficacy of the Red Peruvian Bark, &c. by William Saunders, M. D. &c. &c.

T

Experiment I.

O an ounce of red bark, reduced to a fine powder, were added fixteen ounces of diftilled water; and after remaining together twenty-four hours in a Florence flafk, the liquid was carefully filtered. The fame experiment was made with the Peruvian bark commonly in ufe.

The colour of the two infufions was very different; that made with the red bark being much deeper, The taste and flavour of the infufion of the red bark were confiderably more powerful than of the other. In the opinion of many gentlemen who tafted the infufions, the cold infufion of the red bark was more fenfibly impregnated than even the frongeft decoction of the common bark,

Experiment II.

To two ounces of the cold infufion of the red baik, were added

twenty drops of the Tinctura Florum Martialium. It immediately became of a darker colour, foon loft its transparency, and after a short time precipitated black powder.

Experiment III.

To two ounces of the cold infufion of the common bark were added twenty drops of the Tinctura Florum Martialium in the fame manner as to the other. It retained its tranfparency fome time, and afterwards became of a dark colour; but there was no precipitation from it as from the laft.

Experiment IV.

To an ounce of red bark, re, duced to coarfe powder, were added fixteen ounces of diftilled water, and after boiling until one half was evaporated, the liquid while hot was ftrained through a piece of linen. The fame experiment, under fimilar circumftances, was made with the common bark. The fuperior tafte and flavour of the decoction of the red bark was equally obfervable with that of the infufion. The decoction of the red bark, in cooling, precipitated a larger quantity of refinous matter than the decoction of the common bark.

The difference of colour was likewife very distinguishable.

Experiment V.

To one ounce of red bark, reduced to a coarfe powder, were added eight ounces of proof fpirit; and, after standing a week together, the tincture was filtered.

The fame experiment, under fimilar circumftances, was made with the common bark. The tincture of the red bark, both when tafted by itself and under precipitation by water, had more flavour and tafte than that of the

common bark.

The tincture from the red bark is of a much deeper colour than the other.

Experiment VI.

To each refiduum of the above tinctures were added eight ounces of proof fpirit, which were infufed in a moderate fand heat for the fpace of twenty-four hours, and afterwards allowed to remain together a week, occafionally agitating them. The tinctures were then poured off; that of the red bark evidently appearing to be the strongest.

The tinctures both of Experiments V. and. VI. were by a gentle heat evaporated to the confiftence of a refinous extract.

The extract from the tincture of the red bark was of a smooth, homogeneous appearance, not unlike the Balfam of Peru when thickened the flavour and taste of the original tincture were entirely preferved in it.

The extract from the common bark had a very different appearance. It feemed coarse and gritty, and by no means fo characteristic of its original tincture.

The quantity of extract procured from the red bark was confiderably greater than from the fame quantity of common bark; but, as the refiduum of neither was rendered entirely inert, the abfolute quantity could not be afcertained.

Experiment VII.

A tea fpoonful of each of the tinctures, prepared by experiment 5th, was added to two ounces of water: the refinous precipitation from the red bark was not only more copious, but fell more quickly to the bottom of the glafs than that from the other; and yet what remained ftill difolved in the water, was infinitely more in the red bark than in the common bark, fo far as we could judge from the taste and flavour of both.

Experiment VIII.

In imitation of the experiments of my ingenious friend Dr. Percival, I added to two ounces of the watery infufion of each bark a few drops of the Sp. Vitriol, ten. The acid loft its taste more in the infufion of the red than in the common bark; fo that there were more obvious appearances of its being neutralized.

Experiment IX.

A decoction of both red and common Peruvian bark was prepared, by taking an ounce of each and boiling them in a pint and a half of water to one pint. The former had greatly the fuperiority in ftrength and power, as mentioned in a preceding experiment. A pint of fresh water was added to each decoction; the boiling ftill continued till that quantity was evaporated. The decoction of the

com

mon Peruvian bark feemed gradually to lofe its fenfible qualities, while that of the red bark ftill retained its own.

The fame quantity of water was added as before to each, and the decoction repeated until a gallon of water was exhaufted; at the expiration of which time, the common Peruvian bark was rendered almoft taftelefs; the red bark ftill retained nearly its former fenfible qualities. This experiment proves that the common practice of boiling the bark is hurtful to its powers.

By my defire Mr. Skeete, a very ingenious and attentive young gentleman from Barbadoes, and a tudent of medicine in Guy's Hofpital, made feveral experiments in order to ascertain the comparative antifeptic power of red bark with the cominon Peruvian bark; and he found that the infufion of red bark preferved animal matter much better, and for a longer time, than the infufion, or even decoction of the common bark: indeed, the decoction of common bark, after its powdery part had fubfided, was lefs bitter, and preferved animal matter for a fhorter time than the infufion of the fame bark. His experiments were conducted with great accuracy, and the refult of them were fubmitted to the examination of many gentlemen at Guy's Hofpital.

The conclufions to which the above experiments evidently lead,

are,

Firft, That the red bark is more foluble than the Peruvian bark, both in water and fpirit.

Secondly, That it contains a much larger proportion of active and refinous parts.

Thirdly, That its active parts, even when greatly diluted, retain their fenfible qualities in a higher degree than the most faturated folutions of common bark.

Fourthly, That it does not undergo the fame decompofition of its parts by boiling as the common Peruvian bark.

Fifthly, That the red bark is more aftringent than the common Peruvian bark.

Sixthly, That its antiseptic powers are greater. As an additional proof of this, it may be proper to obferve here, that both its cold infufion and decoction preferved entire their bitter and other medicated powers in the month of June, in the elaboratory of Guy's Hofpital for five weeks, and perhaps for a much longer time, while a decoction of common bark gave evident marks of a change in a few days. In the decoction of red bark, the powder, which is feparated during the cooling of it, remains intimately diffused through the liquor, which therefore continues loaded and turbid when at reft. In the decoftion of common bark, the powder quickly fubfides to the bottom; the red bark therefore contains in it a large proportion of mucilaginous parts, fuch as have been propofed by the late Dr. Fothergill, to be added to the decoction of the common Peruvian bark, in order that it may remain turbid when at reft, and thereby that its refinous parts be more perfectly fufpended in the body of the liquor. It is obvious that this circunftance will favour exceed ingly the action of the stomach upon it.

The advantages therefore to he expected