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dried in a flow and gradual manner, which is now found 

 to be a miftake ; and that as quick a drying as is confiftent 

 with the fafety of the vegetable fubftance, preferves beft the 

 efficacious qualities of the plant.* 



Too much light is indeed thought to do injury, as it 

 impairs the colour, and perhaps (though even that is du- 

 bious) dilfipates fome of the finer and more efficacious 

 parts -, but culinary heat is free from that objection, and at 

 the fame time poffefles all the advantages of quick drying. 



I have been lately informed by a gendeman of great ex- 

 perience in pharmacy, that the collcwtors of fimples, about 

 London, now furnilh dried herbs in infinitely greater 

 perfection than formerly; their flavour, colour, and odour 

 being fcarccly inferior to that of the frefh vegetable, which 

 is owing entirely to their being quickly dried. The appli- 

 cation of this hint to thofe who raife and drefs our indi- 

 genous rhubarb for the market, may be of fervice. 



The firft and fccond experiments (hew the fimilarity of 

 the rhubarbs, No. I. and No. II. to the Turkey and Kafl- 

 Indian, as far as regards thofe parts water is capable of dif- 

 foiving. The Turkey rhubarb, however, appears to con- 

 tain the largeft proportion of any, of matter foluble in 

 vater, and to retain moft of an aromatick flavour. 



The tliird and fourth experiments fhew the proportion 

 which the gummy, and perhaps inert, matter bears to the 

 refinous, and probably the more active. No. II. contains, 

 according to experiment IV. the largeft proportion of gum 

 or mucilage, and the Eaft-Indian die leaft. No, I. and 

 the Turkey were nearly alike; but I fufped the refm was 



* Lewises preface to hU Mat. Mcdica.<»Ncw Difpenfatory, ad edit, p; zgi. 



not 



