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difpelling. This motion, and thefe ofcillations, were however but of fhort duration.

Perfons have been met with, who having been bit by a viper, have remained paralytic in fome particular part of the body during life. A fhort time ago a woman in TUSCANY, who had been bit in the little finger by a viper, became, after various other complaints, paralytic throughout the whole right fide of her body, and could never be cured. In a word, it is certain that all those who have met with this accident complain foon after of an univerfal weakness. Their muscles refuse their office. They become dull and heavy, have no longer the free exercise either of body or mind, and fall infenfibly into a kind of lethargy: fo true it is, that this venom induces a pally of the muscles, and robs them of their active property, called by the moderns animal irritability.

The afpic alfo kills by occafioning a sudden drowsiness and univerfal weakness, followed by death, in the animal ftruck by it. Hence it seems that all the poisons fupplied by the animal kingdom, occafion death by exbaufting the irritability of the moving fibres.

But of all the poisonous animals hitherto known, the polypus feems to poffefs the most powerful and active

venom. However irritable these creatures may be in other cafes, and difficult to kill, the polypus fucceeds inftantly in extinguishing the principles of motion and life in water-worms. What is very fingular, its mouth or lips have no fooner touched this worm than it expires, fo great are the force and energy of the poifon it conveys into it. No wound is however found in the dead animal. The polypus is neither provided with teeth, nor any other inftrument calculated to pierce the fkin, as I have affured myself, fays FONTANA, by obferving it with excellent microscopes.

If we reflect on the effects of OPIUM, its mode of action will also clearly illuftrate this fubject. That vegetable juice, if taken in a large dose, begins by rendering an animal weak and torpid, and foon kills it by exhaufting the irritability of the mufcular fibres, as I have feveral times obferved in animals with cold blood, and as the famous BARON DE HALLER demonftrated a long time ago, even in those that have the blood warm.

The fymptoms and accidents that follow the bite of the viper, do not differ effentially from those I have just spoken of, and may at leaft induce one to fufpect that the venom of that animal likewise kills by totally destroying the irritability of the fibres.

Both

Both of them

and vomiting t.

act by exciting violent convulfions Each conveys an univerfal debility

into the organs. They render the inufcles paralytic, make the animal heavy, and finally bring on lethargy

* Convulfions appear to arife, fays FONTANA, from the destruction at different times, and in an irregular manner, of the irritability of the muscular fibres. It has been unjustly attributed to a fuperabundance of animal fpirits. Weak languishing animals, that die from hunger, perish in dreadful convulfions. It is befides certain, that men and women of a delicate and weak frame are always the most subject to convulfions; and it is not poffible to suppose in these persons fuperabundance of animal spirits.

We know that all the muscles, even in a relaxed state, preferve notwith ftanding a certain tenfion of their fibres, which, when they are cut, never fail to contract themselves and enlarge the wound. When a muscle becomes paralytic it lengthens, and its antagonist then contracts the more; which fhews that repofe of the muscles depends on the equilibrium of strength betwixt the different mufcles, and betwixt their different fibres. The powers thus balanced destroy and renew themselves at every instant, without producing any motion or fenfible change. This natural tension of the muscular fibres arifes either from the nervous clectricity (fee Part I. Sect. XII. p. 114), or from the exact diftribution of well oxygenated blood in the whole substance of the muscles. If these muscles do not receive the fame proportion of well oxygenated blood, or if the arterial blood be distributed with an unequal quickness and energy amongst them, the equilibrium of the mutual efforts of the muscles is immediately destroyed; the strongest of them contract; and hence arife convulfions and agitations of the whole frame. It is for this reafon, that those who die of an hæmorrhage, as well as those who perish by poison, or by breathing mephitic airs, are seized with convulfions: for it certainly is not probable that the lofs of blood, and of ftrength, fhould bear an equal proportion in every part, in every muscle, and in every fibre, whilst the circulation itself is unequal, and the principle of irritability is dependent on, or derived from, the blood.

+ Those who breathe for any length of time mephitic air are seized first with faintnefs, and if life becomes not immediately extinct, are attacked with vomiting. Vide Part I. p. go.

and death. It avails nothing to animals with cold blood, that they are endued with an obftinate life, and are capable of preferving that, as well as motion, after they are cut to pieces. If either of these poifons attacks the principle of their motion, that is, destroys OXYGEN upon which the IRRITABLE PRINCIPLE depends, they die speedily, all motion is annihilated in them, and their parts will no longer give any figns of life. Their body, it is true, will preferve its organization; but an organized body that has loft its motion, is truly a body without life, and the body then differs in nothing from a foffil, or any other dead matter, for all this affemblage of veffels, fo many different organs, and this aftonishing ftructure of parts, are no longer of any ufe to the animal, and should be regarded as not exifting, for without IRRITABILITY, there is neither sensation nor life.

It may not be amifs here to inquire a little into the foundation of that memorable doctrine maintained by some philofophers, "THAT OXYGEN IS THE PRIN

66 CIPLE OF IRRITABILITY, AS IRRITABILITY IS THE "PRINCIPLE OF LIFE. Vide the Memoirs of GIRTANNER, P. 211; and the Rev. Mr. TowNSEND'S Guide to Health, p. 306.

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SECT. XXXVI. ·

OF OXYGEN AS THE PRINCIPLE OF IRRITABILITY.

Perhaps from the new chemistry, which is daily unfolding the profoundeft fecrets of nature, and, among the reft, the delicate play of living machinery, a method may be devised of restoring IRRITABILITY to the system. The Materia Medica was formerly supposed to contain distinct fpecifics for the diseases of each separate organ; it is now regarded as little elfe than a collection of evacuants and ftimuli; fo that medicine is become in a great meafure the art of adminiftering drams. Hence it can often only amufe or palliate, and muft fometimes injure, by forcing into motion conftitutions already too much worn. How would our resources be multiplied, if we could give IRRITABILITY as well as STIMULANTS! "But is fo falutary a revolution in medicine poffible ?" I do not know; but it is worth while to enquire.

Dr. BEDDOES.

AFTER having proved that the venom of the viper, afpec, &c. occafion death by destroying the IRRITABILITY of the fibres, we should next examine THE CONDITION OF THE BODY WHEN DEPRIVED OF THIS

PRINCIPLE.

The truly conflituent principles of vegetables are three, 1. HYDROGEN,

2. OXYGEN,

3. CARBON.

I call these conflituent parts, fays the celebrated LAVOISIER, because they are common to all vegetables,

and

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