It is probable the bad consequences which have followed the indiscriminate use of the lancet France, and some other countries, may have contributed in some degree to create the prejudices against it, which are entertained by the physicians in Great-Britain. Bleeding, like opium, has lost its character, in many cases, by being prescribed for the _name_ of a disease. It is still used, Mr. Townsend tells us, in this empirical way in Spain, where a physician, when sent for to a patient, orders him to be bled before he visits him. The late just theory of the manner in which opium acts upon the body, has restrained its mischief, and added greatly to its usefulness. In like manner, may we not hope, that just theories of diseases, and proper ideas of the manner in which bleeding acts in curing them, will prevent a relapse into the evils which formerly accompanied this remedy, and render it a great and universal blessing to mankind? AN INQUIRY INTO THE _Comparative State of Medicine_, IN PHILADELPHIA, BETWEEN THE YEARS 1760 AND 1766, AND THE YEAR 1805. In estimating the progress and utility of medicine, important advantages may be derived from taking a view of its ancient, and comparing it with its present state. To do this upon an extensive scale, would be difficult, and foreign to the design of this inquiry. I shall therefore limit it, to the history of the diseases and medical opinions which prevailed, and of the remedies which were in use, in the city of Philadelphia, between the years 1760 and 1766, and of the diseases, medical opinions, and remedies of the year 1805. The result of a comparative view of each of them, will determine whether medicine has declined or improved, in that interval of time, in this part of the world. To derive all the benefits that are possible from such an inquiry, it will be proper to detail the causes, which, by acting upon the human body, influence the subjects that have been mentioned, in those two remote periods of time. Those causes divide themselves into climate, diet, dress, and certain peculiar customs; on each of which I shall make a few remarks.