C 425 ] 



Exp. III. To each of the above tinftures were now added 

 five drops more of the chalybeate folution ; when the Turkey 

 and Eaft-Indian tinftures became confiderably more black, par- 

 ticularly the former. The tindlure of the Englifh rhubarb ac- 

 quired a deeper brown, particularly No. 1. but by no means 

 equal to the tinfture of the Turkey rhubarb. 



Exp. IV. To illuftrate this more clearly, the four mixtures 

 were ufed as ink, and the names of each were written with theni 

 feparately on writing paper, which paper is inclofed, and accom- 

 panies the four tinftures for the Society's infpeftion. 



Exp. V. To a flout young man, who was troubled witli a 

 painful ulcer in his leg, were given 60 grains of the powder of Eaft- 

 Indian rhubarb, with the ufual regimen : it operated only twice. 



Exp. VI. At the interval of forty -eight hours, he took the 

 fame quantity of Englifh rhubarb No. I. : tliis operated four times, 



Exp. VII. At the like interval, he took the fame quantity of 

 Englifli rhubarb No. II. which operated brifkly three times. 



Exp. VIII. Laftly, he took of Turkey rhubarb only forty-five 

 grains, which however operated four times, though lefs brifkly 

 than the Englifh. All of them tinged the urine alike, and ope- 

 rated without occafioning any naufea, ficknefs, or gripes. 



REMARKS. 



It has already been obferved, that the tincture of the 

 Turkey rhubarb tafted rather more aromatic than the refl; ; 

 and from Experiments I. II. Ill, and IV. it would appear, 

 that it poflefles a fomewiiat higher degree of aftringency 

 than the Eaft-Indian; and that this rather exceeds the two. 

 EngIKh tinctures as to the afiringent quality. For it is 

 the kuov.'n property of fait of ftcel, or copperas, to ftrikc a 

 black colour \vith aftringents, i*nd thut in proportion to the 



deijrec 



