PART II.— PHARMACOGNOSY. 



CHAPTER I. 

 CRUDE DRUGS. 



INTRODUCTORY. 



Pharmacognosy is a term derived from two Greek words 

 which, together, mean a knowledge of drugs. According to mod- 

 ern usage it is generally understood to mean the study of the 

 structure and chemical constituents of crude drugs. 



The origin of the word drug is more or less obscure, but it is 

 now applied to any crude substance which may be employed in 

 medicine, whether of vegetable, animal or mineral origin. 



The NATURAL ORIGIN is the scientific name (generic and spe- 

 cific names) of the plant or animal yielding the drug. In the case 

 of vegetable drugs the natural origin is spoken of as the botan- 

 ical ORIGIN. A vegetable drug usually represents some special 

 part of the plant, but in some instances the entire plant is em- 

 ployed, as chirata. 



The habitat of plants is the region where they grow. Some- 

 times this term is applied erroneously to the drugs themselves. 

 Neither the scientific name of the plant nor the commercial name 

 of the drug may be relied upon as indicating the true habitat of 

 medicinal plants. For example, the specific name of Spigelia 

 marilandica indicates that the plant is found in greatest abundance 

 in Maryland, whereas it is only occasionally met with in that 

 State. In other cases plants are common to a much larger terri- 

 tory than the specific name would indicate, as Prumts virginiana. 

 The geographical names associated with drugs frequently apply 

 to the places from which they are exported, rather than to the 

 habitat of the plant yielding the drug, as, for example, Para 

 sarsaparilla, which is obtained from a plant growing in the upper 

 Amazon region, is shipped to Para, from whence it is exported. 



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