^ , ON PEPPER, 



II. 



On Pepper, 5^* Thomas Thomson, M.D, Communicated 

 by the Author. 



VegetaWeche. NOTWITHSTANDING the great number of labourers 

 who have engaged in the caltivation of chemiftry, the field 

 of that alluring fcience h too extenfive to be fully occupied. 

 While many fubdivifions are left entirely wafte, and others 

 exhibit here and there only faint traces of improvement, fome 

 fortunate fpots, either from their fuppofed importance, or from 

 the influence of fafliion or accident, have been crowded with 

 workmen, and cultivated with enthufiaftic eagernefs. The 

 mineral kingdom has probably engaged the exclufive attention 

 of nearly two thirds of the whole body of pra6tical chemifts: 

 The animal kingdom, in confequence of th^ intimate connec- 

 tion between chemiftry and medicine, has enjoyed a confi- 

 derable fhare of cultivation; but the vegetable kingdom, though 

 furely not inferior in importance, and apparently rather more 

 alluring, has till lately been greatly neglefled, at leaft in 

 Britain. 

 Reafons why Indeed it is not likely that vegetable chemiftry will ever 



this branch muft arrive at the precifion which we have a right to look for in 

 accurate^ than ^^^ analylis of minerals. The conftituents of the latter feem 

 mineral che- fcarcely fufceptible of altering their ftate; but thofe of vegeta- 

 "'^ ^^* bles run progreffively through a regular fuite of changes. — 



Thus the fubftance, which in the embryo ear of corn polTefles 

 the properties of mucilage, appears in the ripened grain under 

 the form oi' ftarch. Between thefe two extremes there exift* 

 an indefinite number of intermediate ftates, through allof 

 which the vegetable matter fucceffively runs. The rapidity 

 and completion of thefe changes depend upon a multitude of 

 circumftances. In no cafe can they proceed exadly in the 

 fame order and at the fame rate unlefs all the circumftances 

 tally. Without this the conftituents of two vegetables even of 

 the fame fpecies, cannot be in the fame ftate, and of courfe the 

 analyfis of each, though conduced with the moft perfect ac- 

 curacy, will by no means exhibit an exatl coincidence. 

 Changes in ve- But even fuppofing the conftituents of two vegetable bodies 

 fftctufeTand ^" ^^^"^^ refped the fame, ftill the analylis of each may lead 

 by reagents. tO 



