334 FALLACIES. 



it was supposed to produce, or to the phenomenon over which 

 its power was thought to be exercised. " Thus the lungs of a 

 fox must he a specific for asthma, because that animal is 

 remarkable for its strong powers of respiration. Turmeric has 

 a brilliant yellow colour, which indicates that it has the power 

 of curing the jaundice; for the same reason, poppies must 

 relieve diseases of the head ; Agaricus those of the bladder ; 

 Cassia fistula the affections of the intestines, and Aristolochia 

 the disorders of the uterus : the polished surface and stony 

 hardness which so eminently characterize the seeds of the 

 Lithospermum officinale (common gromwell) were deemed a 

 certain indication of their efficacy in calculous and gravelly 

 disorders ; for a similar reason, the roots of the Saxifraga 

 granulata (white saxifrage) gained reputation in the cure of 

 the same disease ; and the Euphrasia (eye-bright) acquired 

 fame, as an application in complaints of the eye, because it 

 exhibits a black spot in its corolla resembling the pupil. The 

 blood-stone, the Heliotropium of the ancients, from the occa- 

 sional small specks or points of a blood-red colour exhibited 

 on its green surface, is even at this very day employed in many 

 parts of England and Scotland, to stop a bleeding from the 

 nose ; and nettle tea continues a popular remedy for the cure 

 of Urticaria. It is also asserted that some substances bear 

 the signatures of the humours, as the petals of the red rose 

 that of the blood, and the roots of rhubarb and the flowers of 

 saffron that of the bile." 



The early speculations respecting the chemical composition 

 of bodies were rendered abortive by no circumstance more, 

 than by their invariably taking for granted that the properties 

 of the elements must resemble those of the compounds which 

 were formed from them. 



To descend to more modern instances ; it was long 

 thought, and was stoutly maintained by the Cartesians and 

 even by Leibnitz against the Newtonian system, (nor did 

 Newton himself, as we have seen, contest the assumption, but 

 eluded it by an arbitrary hypothesis), that nothing (of a phy- 

 sical nature at least) could account for motion, except previous 

 motion ; the impulse or impact of some other body. It was 



