Sect. III.] Theory and Praclkc of Physic. 33.^ 



The author has not iDidertaken to explain in what 

 manner the debihty in the w hoU^ of tlie hnietions 

 proves an indirect stimulus to the sanguiferous sy- 

 stem 3 nor how this stimulus operates in exciting 

 the cold stage and spasm, I'he coexistence of 

 atony and spasm in the same vessels is regarded by 

 many as an insuperable diihcult}\ No explana- 

 tion is offered of the mode in which the action of 

 the heart and larger arteries is augmented by the 

 intervention of the cold stage and spasm. The pro- 

 cess by which this augmentation restores the energy 

 of the brain, and extends such energy to the ex- 

 treme vessels, is also left entirely in the dark. His 

 introduction of the vis medicatrix naturu: is liable 

 to almost all the objections of the aniina mtdicu of 

 Stahl, and must be considered as no better than a 

 confession of ignorance. In all these respects, 

 and many others, this celebrated doctrine rests 

 on hypothetical ground. This will appear the 

 more surprising, as the learned author professed 

 to disclaim all those hypothetical opinions which 

 go to the formation of theories ; and seems to 

 have been persuaded that his doctrine of fever 

 was only an induction from a generalisation of 

 facts. 



It would be injustice, how^ever, to Dr. Cullen, 

 not to subjoin that his merits are extensive and 

 universally acknowledged. He was a diligent and 

 faithful collector of facts. His works often contain* 

 admirable descriptions and sagacious discrinnna- 

 tions of diseases. His great excellence seems to 

 have consisted in methodical arrangement. But 

 it is commonly remarked, and apjiarently with 

 truth, that he was much more successful in d m*>- 



