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power of reviving and refufcitating effectually, by the fimple prefence of the water with which they are moistened.

The celebrated BONGUER, in his work on the fhape of the earth, relates to us, from-the teftimony of Father GUMILLO, a jefuit, that a large venomous fnake is found in Peru, which being to appearance dead, and dried in the open air, or in the smoke of a chimney, has the property of coming again to life, on its being exposed for fome days to the fun in a stagnant and corrupted

swater.

I have dried, fays FONTANA, the worm called feta equina, or, according to LINNEUS, gordius, feveral times in the open air, without leaving it there too long; it had lost almost all its bulk and weight, and was become like a bruised and dry straw: its fkin had shrunk so as to leave no fenfible cavity, and it had no longer any fign of life and motion. I returned it into water, where, in less than half an hour, it recovered its bulk and weight, and foon afterwards difcovered unequivocal and permanent figns of life. I have fince found a number of other small animals, either on the tops of houses, in earths, or in water, which, in the fame way, alternately lose and 7

recover

recover the use of their organs on being dried, and afterwards returned again into water.

The phyfician ought not, however, to confound with each other these two different states; that is to fay, the putrefaction of the parts, and the deficcation of the organs. In the first the animal is dead for ever; in the second it may yet again return to life. We do not know any power, Nature herself does not disclose any, that can recompofe an organ that is destroyed and entirely decomposed and putrid. This is what has never yet been accomplished or feen. We have therefore every poffible reafon, not only to believe an animal that is reduced to this ftate dead, but likewife to believe it dead for ever. But if the animal is fimply dry, if there is no phyfical disease in its organs, if the component particles of the different parts still preserve their respective fituations, the animal may in this cafe very well return to life; to which effect it is only neceffary that the organs receive a fufficient degree of OXYGEN, which we know to be the principle of irritability and of life.

We have yet a ftronger evidence of the doctrine advanced in this Section from the following experiments with the venom of the viper.

I pierced,

I pierced, fays FONTANA, one of the fore feet of a land turtle that weighed four pounds, with an American arrow, which I left there for half an hour. In another hour it scarcely feemed alive, and in two appeared quite dead. After an interval of ten hours, I removed with a fharp inftrument the inner fhell, taking care that all the fleshy parts fhould be as little torn as poffible. The heart was still, and I fcarcely found any motion in the auricles. But to my great surprise, the heart, together with the auricles, recovered all their force, and continued in strong action fix hours inceffantly; the auricles kept in motion two days, that is to fay, as long as they moistened by OXYGENATED BLOOD which flowed from the neighbouring arteries.

I then pierced the fore foot of a land turtle that weighed a pound and a half with an American arrow, In eight minutes it could fcarce move, and in a quarter of an hour was to all appearance dead. When the feet and neck were stimulated, they difcovered a flight degree of fenfation. Having opened the thorax, I found the heart and auricles quite motionlefs. I touched the heart thrice, and it contracted itself once each time. On freeing it from the membranes, it began to move very brifkly, and continued to do fo for feveral hours. I

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covered

covered it with the inner fhell, and in twenty-four hours found it again motionlefs. I pricked it once with a needle, it contracted itself but a fingle time; I pricked it again, it contracted itself afresh, and continued to do fo every time I pricked it. I left it expofed to the air for three minutes, and it then began to move itself, continuing a very brisk motion for several hours. I covered it afresh with the fhell, and on uncovering it four hours after, found it motionless. I then left it again in the pure air, and in a fhort time, and of itself, it recovered its ofcillations, which continued for fix hours. I again covered it with the shell, and on uncovering it two hours after, found it without motion. I then covered it with water, which I kept on it for ten minutes, without its producing any change. I drained off the water, and the heart was scarcely left in the air a minute, when it began afresh to move brifkly, and continued to do fo feveral hours.

This fucceffion of motion in the turtle, deprived of its IRRITABILITY by the poifon of the ticunas, produced by the fimple contact of atmospheric air, if it does not

In this cafe no decompofition of the water took place; but it proves that it was not moisture in the first experiment that re-excited the movements of the heart.

decifively

decifively prove that the IRRITABLE PRINCIPLE is derived from the oXYGEN of the air, it nevertheless goes to prove, that the air is a very active principle in awakening the IRRITABILITY of the muscular fibres and of the heart, as was maintained in Section XXXII. page 340.

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