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parated the thigh from the trunk, we suspend the course of the venous blood, by compressing between two fingers the crural vein, we lessen, and even totally suspend, the production of the effects. The blood of an animal, in which the signs of action of the upas is developed, contains then, some portion of poisonous matter; indeed, it may be said to be really poisoned. It were curious and interesting to know, if this blood carried into the circulatory system of a healthy animal, would produce effects similar to those it had upon the animal itself. At first sight, we are led to believe that this is extremely probable, even that it is certain. The following experiments will shew with what care we ought, in physiology, to distinguish that which is probable, from that which is proved by experiment.

We passed the arterial blood of an animal, in which the tetanus caused by the upas was manifest, into the ju gular vein of a healthy animal; the transfusion lasted near twenty minutes, so that the healthy animal received a very considerable quantity of poisoned blood, which at the first moment of the experiment, was of a red and vermillion colour, and which afterwards became violet and black, when the upas had produced asphyxia. There did not, however, appear any irritation of the spinal marrow, and the animal only experienced what happens in common transfusions, made with care. I mean, that it had, for some hours, a very marked acceleration of the inspiratory and expiratory motions, as well as a very abundant pulmonary exhalation. Frequently repeated, this experiment has always produced the same results.

We were now certain, that the arterial blood of

animals, poisoned by the upas tieuté, the nux vomica, or the bean of St. Ignace, was not susceptible of producing similar effects on other animals; it would not be, perhaps, the same with the venous blood. It may be presumed, that the respiratory action changed the nature of the poisonous substance; and this alteration might, to a certain degree, give the reason, why the transfusion of the arterial blood of animals poisoned by the strychnos, is not followed with bad effects,

This circumstance did not take place with the venous blood, which returns from the part where the poison has been introduced. After the experiments reported in the memoir upon the upas, and in this, it is impossible to doubt, that this blood does not transport the poison to the lungs. It is very probable, that introduced into the circulatory system of another animal, it would produce effects similar to those which it caused upon the animal on which the inoculation of the poison was made.

A small piece of wood covered with two grains of upas tieuté, was stuck into the thick part of the left side of the snout of a dog. Three minutes after this introduction, we passed into the venous system of another dog, the blood of the jugular vein of the side where the introduction of the poison had been made. The transfusion commenced about one minute before the first signs of the upas; it did not cease until the death of the animal who experienced it. No appearance of irritation of the spinal marrow was perceived in the animal who received so great a quantity of poisoned blood.

Although these experiments were repeated several timeş,

with variations in the mode of introducing the poison, we never could perceive in the healthy animals, who had suffered the transfusions of poisoned blood, any thing which resembled the effects of the strychnos.

Results so positive, appear to us of a nature to warrant the conclusion, that the venous blood of animals poisoned by the upas, the nux vomica, and the bean of St. Ignace, is no more capable than the arterial blood, of producing upon another animal the effects which it will cause upon the animal from which it was taken.

If there still remained any doubts, they would be removed by the following experiment, which was repeated

several times.

As in the experiments above related, we separated from the body the thigh of an animal, isolating as before the crural artery and vein; we introduced the poison into the separated foot, and transfused the blood of the crural vein into the jugular vein of a sound animal. The passage of the blood from one animal to the other, lasted more than ten minutes, a time more than sufficient for the production of the effects of the upas. But no sign of the action of this poison was perceived, either in the one or in the other animal. The one preserved perfect health, the other died in a few days, in consequence of the amputation of the thigh, and from the loss of blood which was transfused.

It must not, however, be thought, that in this experiment the transfused blood, by some particular cause, had

no deleterious properties, for the following experiment proves the contrary.

As in the preceding experiment, I separated the thigh from the body; three minutes after introducing the poison into the foot, I passed the blood of the crural vein into the jugular vein of another animal; the transfusion was prolonged five minutes without producing any effects. I then stopped it, and disposed things in such a manner, that the blood of the crural vein should return to the animal to which it belonged. Almost instantly this animal exhibited evident signs of the action of strychnos on the spinal marrow.

From the different experiments reported in this memoir, we must, I think, conclude,

1st. That the lymphatic vessels are not always the route followed by foreign matters, to arrive at the sanguiferous system.

2d. That the blood of animals, upon which the bitter strychnos have produced their deleterious effect, cannot produce any fatal effects upon other animals.

As to the explanation of this singular phenomenon, it would be, I think, premature to give it at present. In physiological science, we ought to be sparing of conjectures, and prodigal of facts.

MAGENDIE, D. M. P.

Note. This memoir has received the approbation of

the Institute.

IV.

An original paper of the late Lieut. Gov. COLDEN, on a new method of PRINTING discovered by him; together with an original letter from the late Dr. FRANKLIN, on the same subject; and some account of STEREOTYPING, as now practised in Europe, &c. by the Editors of the Register.

WE are gratified in being able to lay before our readers the following paper, entitled "New method of Printing," found among the papers of the late lieut. gov. Colden, and addressed to Dr. Franklin, together with a letter in reply from Dr. Franklin, lately presented to us for publication by C. D. Colden, Esq. of this city. ED.

"NEW METHOD OF PRINTING.

"As the art of printing has, without question, been of very great use in advancing learning and knowledge, the abuse of it, as of all other good things, has likewise produced many inconveniences. The number of books printed on the same subject, most of which are nothing but unskilful and erroneous copies of good works, written only for ostentation of learning, or for sordid profit, renders the path to knowledge very intricate and tedious. The reader, who has no guide, and the greatest number have none, is lost in the wilderness of numberless books. He is most commonly led astray by the glaring appearances of title pages, and other artifices of the mystery of bookselling.

"It is likewise a common complaint, that a poor author

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