2s6 PRINCIPLES OF VEGETATION. 



enfuring fccurity to the adventurous mariner, amid the fwellings of the 

 mighty deep. 



It is evident, that to underftand, though but remotely, the relations 

 of thefe fo different fubjefts, difcrimination is both defirable and ne- 

 cefTary : fince they are not alike, we mayjuftly feparatc the different, 

 and combine the limilari to accomplifh which purpofe is the defign of 

 botanical fyftems. 



Smell andtafte give us fome intimation of the nature and qualities of 

 plants. An agreeable tafte or fmell is feldom accompanied with noxious 

 qualifies; on the other hand, when thefe fenfes are difagreeably affed:ed, 

 the qualities are generally more or lefs noxious, being either purgative, 

 emetic, or poifonous. Plants that have a fweet tafte are generally nu- 

 tritive; thofe that have a fak talle are warm and ftimulant. Plants of 

 an acrid tafte are corrofive; but, when deprived of their acrimony by 

 drying, fome of them become fit for food. Bitter plants are alkaline, 

 flomachic, and fometimes of a fufpicious nature. Acid plants are cool- 

 ing, and allay thirft j but thofe of an auftere tafte are aftringent. 



The colour and afped of plants throw fome light upon their nature. 

 Flowers or fruit of a red colour are generally acid. Yellow flowers indi- 

 cate a bitter tafte. Plants that have green flowers are crude ; thofe of a 

 pale colour are commonly inftpid ; thofe of a v/hite colour are generally 

 fweet i and thofe whofe flowers have a gloomy and difmal afpeifb, are 

 moftly poifonous. 



In order to bring the numerous tribes of vegetables under certain 

 clafTcs or denominations, various methods have been adopted by dif- 

 ferent authors. Some have clalTed them by the figure of their roots ; 

 fome by the caulis or ftems; fome by the leaves. Linnaeus has pre- 

 ferred the parts of frudlification, becaufe thefe are not only the moft cf- 

 fential, but likewife the moft univerfal. 



This method of clafiing is preferable to any that has been propofed, 

 on many accounts. It is found by experience, that plants which are dif- 

 tinguift»ed by the fame charafters in the flower and fruit, have the 

 fame qualities, though not always in an equal degree as to ftrength or 

 weaknefs ; fo that, upon infpe(5lion of the flower and fruit, a botanift can 

 determirre a priori the effects that will refult from the plant when taken 

 into the llomach. 



This method of reducing plants to clafTes, genera, and fpecies, is 

 founded upon th? fuppoficion that vegetables propagate their fpecies in a 

 manner fimilar to that of animals. Linnaeus endeavours to fupport this 



, hypothcfis 



