iO GENERAL PRINCIPLES. 



'2, Incompatible Substances are seldom or never found in the 

 same plant. 



23. Every plant has a peculiar and specific mode of action on 



the human body, in health or disease. 



24. Even cong^eneric and consimilar species have their modi- 

 fied effects at equal doses, which a difference in the dose msy 

 equalizer 



25. The medical effects of the same plant are also modified by 

 the soil, climate, season, and age ; also by exhibition and dose. 



26. Botanical affinities indicate medical equivalents, which may 

 be substituted to each other. 



27. But Experience alone can decide If the substitution will 

 be available and efficacious, and teach when and how it ought to 



be made- 

 ^28. Vegetable Equivalents a*re either botanical or medical, and 



each of three degrees. 



29. In Botanical Equivalents these three degrees are : 1st Co2f- 

 0£j!fEBic, belonging to the ^&me genus : 2d Affii-iated belong- 

 ing to different genera of the sajiie family- 3d Rejiote, belonging 



to remote genera. 



20. Medical Equivalents have the degrees of 1. Specific or 

 having exactly the same value, 2. Simieak or producing the same 

 effects, 3. CoxsiatiEAR or producing effects somewhat different. 



31. EVEKT MEDICAL PLANT IS A COHPOrXD MEDICI^TE PBEPABED 



BT THE HAsDs OF XATURE, in the most Suitable form for exhibi- 

 tion and efficacy in suitable cases. 



32, Medical substances becoming more powerful by admixture, 

 those which enter by vital action into the organs of plants, are 

 rendered more powerful by intimate combination. 



33, By combining several medical plants in prescriptions their 

 effect is increased. 



34, Nauseous or noxious plants may be rendered grateful and 

 available by combination with others of a different character. 



35, But all combinations must either coincide op correct each 

 other, else they are superfluous and useless. 



36, When too many substances are mingled, or several that do 

 not well coincide, they often impair each other. 



Sr. The combination of substances which exert a chemical ac- 



