Page:Philosophical Transactions - Volume 002.djvu/64

 the Cava, that had been made in the first Experiment. We perceived, that this Channel of Communication came from the Ductus Thoracicus, at the lace of the fourth Vertebra of the Back. But to be the surer of it, we made the following Experiment.

3. I compressed with my fingers the Ductus upon the fifth descending Vertebra of the Back; and M. Gayant having blown into the Quill, which was upon the seventh, the wind passed not to the Kidney, nor to the Emulgent Vein. Which made us conclude, that the Communication was not beneath the fifth Vertebra, Then I compressed with my fingers the Ductus Thoracicus and the Vena Cava upon the third descending Vertebra; and the Emulgent swelled, when M. Gayant blowed into the Quill: Which gave us more strongly to believe, That the place of the Ductus Thoracicus, whence goes the Channel of Commerce with the Emulgent, was between the third and fifth Vertebra of the Back, as the wind had informed us in the second Experiment.

To be yet more assured thereof, M. Gayant split the Ductus Thoracicus upon the third Vertebra of the Back, and having blown into it at the Quill, the wind came out at the Axillary Vein, and the Ascending Cava; but the Emulgent swelled not at all.

We made a fourth Experiment, which seemed very curious to us, and will not be miss to relate here; viz.

4. M. Gayant having blown into the Aorta, whereof all the branches, that had been cut, were tied up, it swelled immediately, and the Emulgent Artery grew tumid at the same time: but the wind, that was protruded thorow the Emulgent Artery into the Left Kidney, returned not into the Emulgent Vein; which taught us, that the Blood often passeth, where the Air does not.

We have an evident proof of it in the Kidney, since that the Blood of the Emulgent Artery, which goes to the Kidney, returns thorow the Emulgent Vein into the Vena Cava, pursuant to the Rules of the Circulation of the Blood; and that the Air propelled thorow the Emulgent Artery into the Kidney, comes not back thorow the Emulgent Vein into the Vena Cava. We