164 animals' systems differ, [book r. 



But, " the animal system," as a term, or in fact, 

 may be taken to imply as well that of all animals 

 as particular kinds of animals — descending some- 

 times (not improperly) to individuals of those kinds. 

 Some persons, however, descend still lower, and 

 the term " system" has been sadly misapplied, and 

 bandied about from one thing to another, until it 

 is brought to describe particular parts or portions 

 only of the individual's system. That of the dog kind, 

 the horse kind, and mankind, are good and proper 

 distinctions, for the system of animal life differs in 

 all three : they are not in every case moved in a 

 similar manner by the same class of medicines ; 

 whereby we first perceive that their systems differ, 

 and we examine the dead subject of either kind (as 

 in the preceding chapter), to find out how this takes 

 place, and in what degree, and we regulate our 

 practice conformably to the discoveries so made. 

 The several individuals, too, of the same kind, 

 have particularities in their respective systems, 

 arising from habit, from country or climate, or 

 from crosses*, that demand our serious analytical 

 reasoning, in the application of similar remedies, 

 and adapting their proportions to the removal of 

 similar symptoms. Thus it is, a sensible difference 

 is known to exist between the constitution of a cart- 

 horse and a blood-horse, between a galloway and 

 a hunter ; each requiring accurate discrimination 



• TJic system of the same individual, also, may undergo changes 

 by time ; so that a medicine may operate differently at present from 

 what it formerly did. 



