^6 The Jrt of Farriery 



Difer-fc laft^ thefe Changes muft have a Tendency, 



either to an over-great Rarefaftion or Thinnefs, or 



elfe to the over-great Thicknefs and Vifcidity of 



the Blood. 



A Fercr A Fever may likewife proceed from an Inequality 



may pro- of the Subftance of the Blood, whereby fome Parts 



ceed from of it pafs,more eafily than others through the fmaller 



Iky oflfTe' ^^^^*'^s. I fay, this may produce the Symptoms 



Subftance common to Fevers ; as violent and exceffive Heat, 



of the and beating of the Arteries, ^c. ; and this is fo 



Blooi. clear and evident, that it needs no Manner of Proof, 



fmce Heat muft alv/ays be the EfFeft of Motion. 



Some former Authors ( and thole of Note too ) 

 have taken infinite Pains, to (hew the different Kinds 

 of Fevers from rarefied or thin'd Blood, as alfo thofe 

 prifing from the vifcid and thick : But in my humble 

 Opinion, though I have confider'd them over and 

 over again, they only argue to fhew their Learning : 

 For the JEtioIogy or Dodlrine teaching (or rather 

 pretending to teach ) us the Knowledge of the Caufes 

 cf Diilemper?, is a dark and abflrufe Doftrine ; and 

 really it is no eafy Matter to fhew, how many F~ts 

 go to an Ounce. Yet the Reafoning and Arguments 

 of many upon the aforefaid Term, amounts not to 

 a quarter Part cf what's pretended ; nor can fuch in 

 riny Manner or Shape edify or improve our Under- 

 ft^nding ; fmce they only confiit of unintelligible Me- 

 taphors wliich rather puzzle and perplex the Reader 

 than Gtherwife. Indeed I own, that the Art of 

 •Medicine is brought at laft to very great Perfedion, 

 and many Things proved plain to a Demonflration : 

 But I think, with Submiffion, that theie Improve- 

 ments and Difcoveries go no farther, than fhewing us 

 the Force and Manner of Operation of Medicines. 

 And in this Part of Knowledge, there is no Doubt, 

 but Natural Philofophy has the greateft Share. I 

 ihail therefore fhun, as much as in me lies, all daik 

 and abfirufe Reafomngs, as well as unintelligible 

 Terms, and fo proceed to give my Opinion upon what 

 is CiUled a Sir-jple, or rath<?r Sjrnptirfiatick Fe'uer. 



CHAP. 



