398 INTRODUCTORY LECTURES. 



state of medicine ; but the progress of this was slow. The 

 knowledge of the circulation did indeed necessarily lead to the 

 consideration as well as to a clearer view of the organic system 

 in animal bodies ; which again led to the application of the 

 mechanical philosophy towards explaining the phenomena of the 

 animal economy; and it was applied accordingly, and continued, 

 till very lately, to be the fashionable mode of reasoning on 

 the subject. Such reasoning, indeed, must still in several re- 

 spects continue to be applied : but it would be easy to shew that 

 it neither could, nor ever can be, applied to any great extent in 

 explaining the animal economy ; and we must therefore look 

 for other circumstances which had a greater share in modelling 

 the system of physic. 



With this view it may be remarked, that, till the period just 

 now mentioned, every physician, whether Galenist or chemist, 

 had been so much accustomed to consider the state and condi- 

 tion of the fluids, both as the cause of disease and as the foun- 

 dation for explaining the operation of medicines, that what we 

 may term an Humoral Pathology, still continued to make a 

 great part of every system. In these circumstances, it was soon 

 perceived that chemistry promised a much better explanation 

 than the Galenic or Aristotelian philosophy had done ; and, 

 therefore, while the latter was entirely laid aside, a chemical 

 reasoning was every where received. Lord Bacon, with his 

 usual sagacity, had early observed that chemistry promised a 

 great number of facts, and he thereby gave it credit ; whilst the 

 Corpuscularian philosophy, restored by Gassendi, readily united 

 with the reasonings of the chemists ; and the philosophy of Des 

 Cartes readily united with both. From all these circumstances, 

 an humoral, and chiefly a chemical pathology, came to prevail 

 very much till the end of the last century ; and has indeed 

 continued to have a great share in our systems down to the pre- 

 sent time. 



We have thus deduced the history of physic through many 

 ages, in the course of which it has appeared under various 

 forms. It has had the fate of literature in general, to be some- 

 times neglected and sometimes cultivated, and when the last 

 took place, it has always followed the fate of natural philosophy, 

 from which it is inseparable. For it is difficult for me to be- 



