GENERAL PRINCIPLES. 11 



lion on each other, must be avoided, unless a peculiar medical 



result is required. 



38. When an unexpected result happens by a combination of 



substances, it must be corrected by suitable changes. 



39. The active principles of medical plants may be obtained in 

 a concentrated form by chemical operations. 



40. Wh^n these active principles are obtained, their effects 

 are stronger and quicker; but less congenial to the human frame, 

 than in their natural pristine combination. 



FOURTH SECTION— MEDICAL PROPERTIES* 



1, The medical properties were detected by chance, or as- 

 certained by indication, and confirmed by experience. 



2, There are four kinds of indications, 1. Botanical, 2. Che- 

 mical, 3. Medical, 4. Evident. 



are 



proximate or remote, and teach us Botanical Equivalents. 



4, Chemical indications result from analysis and decomposi- 

 tion : when the same elements and substances are found in equal 

 proportions ; the presumption must be that chemical equivalents 

 have been detected. 



5. Medical indications are the result of medical inference ; 

 Tfvhen substances act alike or produce similar effects In some 

 cases, they may do the same in other cases. 



6» The most obvious indications are however, those which 

 arise from the Evidbsck of the sensible qualities of plants. 



7. These qualities are constituted by chemical elements, and 



% ^ 



evinced to our senses by contact or effluvia. 



8. Each plant, and sometimes each part of a plant, has a pecu- 

 liar smeli and taste, hardly alike in any two of them. 



9. No plant is absolutely scentless or tasteless, even the most 

 insipid evince themselves to our nose and palate- 



10. The vegetable Orders and Sapors may be classed under 

 two great divisions, GRATEFUL or UNPLEASANT. 



11. Orders may be further divided into six series, and one hua- 



