ON NOSOLOGY. 461 



toms or certain marks. There are many internal affections which, 

 could we discern them, we should certainly mark, but we know 

 them only in consequence of dissection. Vogel, in the con- 

 clusion of his system, remarks, " nee silentio prorsus trans- 

 eunda sunt vitia quaedam occulta, quoe non nisi in cadave- 

 rum sectione se offerunt :" they are, indeed, to be remembered ; 

 but the Nosologist is to be conducted by what are the objects 

 of his senses ; he is never to insert any thing which is the con- 

 sequence of inference ; and however imperfect this may leave 

 our art in this respect, yet this is an imperfection which cannot 

 be remedied. Where these internal affections are to be con- 

 sidered as primary, we mention them as possible causes of the ex- 

 ternal phenomena ; and our experience very often enables us to 

 say with probability when they take place. But they very rarely 

 admit of being inserted in our Nosology. Sauvages, and par- 

 ticularly Vogel, have trespassed against this rule, mentioning 

 diseases which indeed exist, but which were not to be noticed, as 

 being without external marks. Thus Vogel, in establishing the 

 genus Pancreatica, observes, " notae desunt," and thus assigns 

 himself the reason why it should not have been mentioned. 



These are the several errors which, I think, Nosologists have 

 committed ; and you will perceive how, in consequence of them, 

 the genera have been too much multiplied, as has particularly 

 been done by Vogel ; and you will also observe how I had an 

 opportunity of greatly diminishing the number of genera. I 

 know of some, indeed, which in my synopsis are omitted, as I 

 either had no clear or accurate knowledge of them, or could not 

 work them into any part of my system. When Ray attempt- 

 ed his system of Botany, he found that a number of plants 

 would not incorporate ; and hence he found it necessary to add 

 at the end a list of anomalous plants, or, as Linnaeus has it, 

 " incertac sedis." I once thought of subjoining a few of that 

 kind; but, as I am not sufficiently acquainted with many of them, 

 I have omitted them. 



All that I have now said, refers to the important article of dis- 

 tinguishing what in our system are called Genera, but, strict- 

 ly speaking, are Species, or that ultimate concourse of symp- 

 toms which does not, for the most part, admit of a farther divi- 

 sion but into Varieties. I have still to observe, that as I have 



