256 Medkme. 



on in a similar progression till these particles Were 

 diminished down to the finest and most subtile of 

 all, namely, the nervous fluid. According to 

 Boerhaave's opinion, the diameters of the vessels 

 also decreased in the same regular series, perfectly 

 corresponding v^^ith the size of the globules., This 

 explains his frequent introduction of error loci in 

 his account of obstruction and inflammation. But 

 as the notions of Leuwenhoeck on this subject are 

 now generally exploded, so likewise must be the 

 inferences and doctrines grounded upon them. 



It was taken for granted by Boerhaave, and by 

 almost all preceding medical writers, that dis- 

 eases always arise either from some depravity 

 of the fluids, or some fault in the composition 

 or cohesion of the simple solids ; and that wher- 

 ever such disorders exist, they are always sus-- 

 ceptible of a definite character, and placed within 

 the reach of the senses. He believed the fluids to 

 be liable to contamination by acid and alkaline 

 acrimony, and by other morbific matters variously 

 constituted, and to be disordered by lentor and 

 excessive tenuity. The simple solid, according to 

 his doctrine, is subject to very frequent changes of 

 condition, from weakness and excessive stiffness or 

 elasticity, and from laxity and rigidity. 



Boerhaave supposed the proximate cause of 

 fever to consist in a lentor or viscidity prevailing in 

 the mass of blood, and stagnating in the extreme 

 vessels. To this he attributed the cold stage of 

 fevers, and all its consequences. It is true that 

 he afterwards introduced, though with some doubt 

 and hesitation, as an additional part of the proxi- 

 mate cause, an inertia of that portion of the ner- 

 vous flxuid which is destined to the heart. It v/as 

 one of his positions, that the morbid heat in fever, 

 being a symptom only, might therefore be disre- 

 garded. 



