ON NOSOLOGY. 457 



all our systems. It is well known, that the want of precision in 

 the use of terms for a long time retarded the perfection of Bo- 

 tany'; and it has been the greatest merit of Linnaeus, that he 

 gave much more precision, and a determined meaning to almost 

 every word employed in that science, which he did by forming 

 a delineatio plantae, by fixing a term for every part of the plant, 

 and for all the circumstances in which these parts can vary. 

 But we will not bring Nosology to a good condition till some- 

 thing of the same kind, a delineatio morbi, be attempted, which 

 ought to consider all the symptoms that enter into a spe- 

 cific character in another view than that taken by the Patholo- 

 gists, who only trace them to their causes. Here we ought to 

 examine the symptoms more minutely with respect to the variety 

 of their appearance, and affix terms to them accordingly. This 

 however is a difficult task, which my time has not allowed me 

 to accomplish. In the mean time, to avoid, as much as possi- 

 ble, the faults which I mentioned, I have adhered to the terms 

 which have been employed formerly; and I have been as careful 

 to avoid new terms of symptoms as of diseases. 



The fourth rule is, that the characters should be absolutely free 

 and independent of all theory and hypothesis. Sauvages, in his 

 Prolegomena, mentions ten or twelve definitions of Pleurisy, all 

 taken from some view of the proximate cause ; but all of them 

 would now be entirely rejected. By looking into the systems, 

 however, you will perceive that physicians have gone on in the 

 same track of defining diseases by their proximate causes, which 

 are in many cases disputable, and may long be so. Thus, in 

 Juncker's conspectus, every definition is taken from the proxi- 

 mate cause; and I believe most physicians of this country will 

 be of opinion, that nine out of ten of these definitions are falla- 

 cious and good for nothing. This, therefore, we must avoid 

 hereafter : we must endeavour to distinguish diseases indepen- 

 dently of every theoretical view ; for the theory which we em- 

 ploy, however specious, however we may be persuaded of its 

 truth, will not appear in the same point of view to others, and 

 must therefore occasion endless disputes. 



On this subject it may be proper to observe, that I have former- 

 ly expressed myself as if the internal seat might, in consequence 

 of our now knowing it so well from dissections, frequently be at- 

 VOL. i. 2 L 



