ON PEPPER.' 7^^ 



water, we obtain an infufion which I believe holds in folu- 

 tion fcarcely any thing butextrafiive. If this infufion be eva- 

 porated flowly in a fteam heat, it leaves a brown refiduum, 

 which Iconfiderasextra6^ive of ftarch not far from purity. 



1. The infufion is infipid or flightiy fweetifli, and of a fine Aq. folution 

 reddilh brown colour. As the evaporation advances, the co- ^y evap. leave* 

 lour deepens, andthe hquid acquires an acrid flavour, fimilar 



to that of fcorched vegetable matter. This flavour, which in- 

 dicates a commencement of decompofition, is evolved at a 

 very moderate temperature. 



2. If the evaporation be conducted rapidly the extradive is 

 opaque, dark brown, and has a perceptible tafte, and dele- 

 quefces or at leaft attrads moifiure when firft expofed to the 

 atmofphere. But by very flow evaporation I have obtained 

 it in fine femi-tranfparent brown fcales, which are infipid, 

 brittle, and not altered by expofure to the air. 



3. This extradlive diflblves readily in water, but not in al- Soluble in water, 

 cohol. If it be repeatedly diflblved in water, and the folu- |^^f "ot in alco- 

 tions evaporated to drynefs, a fmal! portion of it becomes in- 



foluble in that liquid; but the greater part continues foluble 

 after the procefs has been repeated occafionai ly even for 

 months. 



4. Thisextradlive is precipitated from water by moft of the Precipit. by 

 pietallic falts and by feveral of the earthy folutions. metallic falts. 



It is thrown down in brown flakes by lime-water ftrontian 

 water and alum. Barytes water deepens the colour, but oc- 

 cafions no fenfible precipitate; nor is any precipitate pro- 

 duced by filicated potafs or the magnefian falts. 



It is precipitated brown red by the nitro-muriate of gold, 

 the nitrate of filver, mercury, lead and bifmuth, and by the 

 muriate of tin and antimony. When mixed with the infufion 

 of litmus, the colour becomes red. Ammonia reftores the ori- • ^ 



ginal colour, and at the fame time throws down a copious blue 

 Jake. 



5. When a current of oxymuriatic acid is paflTed through —by ox. mur. 

 the infuficfli of pepper, the brown colour is fpeedily converted "^^ 

 into a pale yellow, and the extractive precipitates in white 



tiakes. The eafiefi method of making this experiment is the 

 following: Put a quantity of the hyperoxymuriate of pofafli 

 into a fmall retort, having a long neck (or a flafli provided 

 with a bent glafs tujbe ground into it) and pour upon it a por- 



-tion 



