LVI. And it is very remarkable, that in the same manner the Galenists endeavour to deduce from experience the necessity of blood-letting in many diseases, they endeavour also to establish the preference, that should be given to drawing blood in particular disorders, from particular veins, such as the hepatic, and cephalic. Anatomy however, makes it as clear as the sun at noon-day, that this preference is not grounded on any solid foundation, and that the cephalic vein bears no more relation to, nor is any more connected with the head, than the hepatic, nor the hepatic with the liver, than the cephalic; and that all the veins of the same arm, communicate indifferently with all parts of the body, as the laws of circulation demonstrate; and as that observation which was pretended to be derived from experience, was founded in mistake, it is not improbable, that that which is generally alledged in favour of bleeding, may be so likewise. LVII. What appears to me is, that the rule so much cried up by the Galenists, and which establishes the necessity of bleeding, in pleurisies, is liable to so many exceptions, that we ought not to regard it as a general one; and we have observed in another part of our works, that in some epidemical pleurisies, it has been found to be evidently injurious. It is but a little while ago, that a learned French physician, whose works are mentioned in the Memoirs of Trevoux, wrote strongly against bleeding in winter pleurisies and peripneumonies; and his reasoning had great weight with some eminent physicians of Paris. I can certify, that in the last winter 1731, when many people were attacked with pleurisies in this country, it was generally remarked, and we received informations to the same effect from all quarters, that those who were blooded died, and that those who were not did well. LVIII. I would have it understood, that I wish all I have said, with respect to the utility or inutility of purging and bleeding in general, should be considered as the sentiments of a man, who takes no side in the dispute, but who proposes what he advances problematically, and with a view of convincing the world, that in order to avoid being misled, they should examine with great attention and exactness, any observation that is alledged to be founded on experience, for this is the principal object I had in view, in writing this discourse.