:5g Oy THE BARK OF 



The materia Let US, tor a moment direct our attention to tlie apolhecarhs 

 medica, but j^j f^g departments, particularly such as are at a distance froiu 



particular! V , . . , , , , . . , , , 



quinquina, very large Cities : they purchase, without suspicion, these barks, 



often adulter- persuaded that they are buying quinquina ; they make us» 



of them ; the operation cannot answer their intention, which 



is attributed to the disorder. You are better acquainted than 



I am witii the consequences resulting from t!ie use of a bad 



article ; why not therefore seek for means to check the evil, 



and to throw light upon so pernicious an abuse ? Though we 



should not entirely succeed, the intention would at least be 



entitled to favor. 



Wliite willow It is long since the white willow and root of the herb ben- 



ortheTerb*^'^* "^' ^^^^*^ ranked among vegetables proper for tanning ; they 



feennet. do indeed, possess qualities similar to those of oak bark ; but 



as much as they differ from this substance in this character, 



by so much do they approximate to quinquina in medicinal 



properties. 



Of the Bark of Willow. 



Exdmiriation The bark of young branches appear to me to be preferable : 

 of willow bark. , , , , , , , , , , rr.. 



they should be used dry and broken. I he water wherein this 



substance has been boiled, acquires a deep yellow tinge, bor- 

 dering on red, which becomes turbid as the liquor cools. 



When several decoctions have been made, the last arc al- 

 ways the most coloured. 

 Its aqueous de- This decoctinn has a bitter and very rough taste. It 

 eoction. feebly reddens tincture of turnsole ; is abundantly precipitated 



by the solutum of glue, and by the carbonates of potash and 

 ammoniac. 

 Habitudes of Acetate of potash and muriate of ammoniac cause but a 



the decoction, |- |^j precipitation ; indeed, with the muriate, it is scarcely 

 with various b i i ' ' ' J 



agents. perceptible. 



If carbonate of potash be added at the time of making the 

 decoction, the liquor assumes a deeper colour. This change 

 seems to result from a disengagement of carbonic acid, which 

 leaving the potash disengaged, causes it to act as an alcali 

 upon the colouring matter of the bark, and upon a portion of 

 Uie resin dissolved by the water ; for the liquor no longer be- 

 comes turbid in cooling. These phosnomena have been ob- 

 served in the decoction of quinquina, by many chemi;;ts. 



Lime 



