8thly, If the different proofs, which Bordeu has given of the influence of the brain over the functions be well examined, it will seem that no one of them is decisive. The sudden interruption of the secreted fluid, in consequence of the division of the nerves of the part, would be the only proof which I should be inclined to admit as positive. Now I am not acquainted with any means of making such division with exactness. We have heard much of an experiment of this nature upon the parotids; but the disposition of the nerves distributed to these glands is such, that I have not been even tempted to repeat the experiment. The testicle is better adapted for the attempt, and accordingly without touching the vessels, I divided the spermatic nerves, but an inflammation and a deposit of matter took place in the gland, and with respect to the secretion of the semen, I could not judge of the effect of the division of the nerves. But here this very inflammation coming on without the influence of the brain, appears to me to infer a possibility of the seminal secretion under the same circumstances. In this experiment, the spermatic artery cannot be separated from the plexus which it receives from the great sympathetic, so intricate is the network of these nerves about it; their division however is of little consequence, as they come from the ganglions. It is easy to break off all communication with the brain, by destroying the lumbar fillets of nerves. I might add a number of other considerations to the above, but here I have to remark that the distinction of the sensibility and contractility into their two kinds is particularly worth attention. In fact, the idea of sensibility in our usual way of seeing things, suggests the idea of the nerves, the nerves again make us think upon the brain, we associate the three ideas, but excepting for the animal life they should not be associated. In the organic life, at least their union is not immediate. I do not mean to say that the cerebral nerves have no influence whatever over the organic sensibility, but I maintain that such influence is not direct and not of the nature of that which is observed in the animal sensibility.