C 431 ] 



Remarks. 



From Experiments I. II. III. and IX. it appears that 

 the refiduum of rhubarb, after a tiniture has been extra^fled 

 from it by proof fpirit, inftead of being reduced to a mere 

 caput mortuum as has been commonly imagined, ftill re- 

 tains its purgative quality in an eminent degree, except 

 the Eaft-India rhubarb, which (in Experiments IV. and 

 IX.) feemed to have entirely loft it by maceration in the 

 fame menftruum. 



Exp. Ylll. fhews, that proof fpirit does not deprive 

 either foreign or Englifh rhubarb of their aftringency. 



From Exp. X. XL XII. and XIII. it further appears, 

 that the Englifh rhubarb is not diverted of its pur-^ative 

 or diuretic power, by boiling water, recElified fpirit of wine, 

 or lime-water; and that the griping quality whicli rhu- 

 barb exerts in certain conftitutions, feems to be increafed 

 by a watery menftruum. The giddir.efs and other fvmp- 

 toms being fo remote from its ufual operation, ought ra- 

 ther to be attributed to peculiarity of conftitu'cion, or other 

 adventitious circumftances. 



From Experiments V. and X. where the diff^erent pow- 

 ders weie given in fiibftance without any tindture being 

 drawn from them, the purgative effects of the Englifh 

 feemed to be at leaft equal, if not fuperior, to thofe of the 

 foreign rhubarbs. The refult of thefc experiments being 

 fomewhat different from fome of the preceding ones, muft 

 be referred to difference of conftitution in the perfons who 

 took fimilar dofcs. 



Experiment VI. Here the well-known property of 

 rhubarb in tinging the urine of a yellow colour (even be- 

 fore its purgative operation takes place) fhews the extreme 



fubtilty 



