PHYSIOLOGY. 215 



foundation of them have been long ago exploded ; and the mo- 

 derns have neither by observation extended the ancient dis- 

 tinctions, nor, though they have often attempted it, have they 

 ever given, so far as I can judge, any happy explanation of the 

 causes or foundation of the distinctions they have so generally 

 adopted. I believe it will be generally allowed, that this part 

 of medical doctrine is still in an embarrassed and undetermined 

 state. 



In treating the subject, philosophy would require that I 

 should, in the first place, distinguish temperaments, by marking 

 the external and observable circumstances which are found with 

 some steadiness to be commonly combined together : but this I 

 find a difficult task ; and what my observation has not been so 

 extensively applied to as to enable me to perform in the man- 

 ner I would wish. I must therefore proceed in another way ; 

 and shall endeavour to consider those circumstances of the in- 

 ternal state of the human body which may give occasion to a 

 difference in the state of the functions, and even in the external 

 appearances which distinguish different men. 



These circumstances may, I think, be referred to five general 

 heads, according as they occur, 1st, In the state of the simple 

 solids (See Physiology, VII. XXVI.) ; 2<%, In the state of 

 the fluids (ibid. CCXLIV. CCLXXIV.) ; 3%, In the pro- 

 portion of solids and fluids in the body ; 4<thly, In the distribu- 

 tion of the fluids (ibid. CLXXX.) ; and, 5thly, In the state of 

 the nervous power, (ibid. XXVII. CXLV.) 



OF PARTICULAR TEMPERAMENTS. 



Temperaments, however, are not to be distinguished by at- 

 tending to any one of these chief circumstances alone ; for the 

 state of any of these is commonly combined with a particular 

 state of all the others ; and it is only by a combination of the 

 particular states of the chief circumstances in the same person, 

 that the temperaments are to be properly distinguished. To 

 explain this, we presume, that in any one person a particular 

 state of the simple solid is pretty constantly combined with a 

 particular state of the fluids, with a particular state of the dis- 



