^: ON PEPPER. 7T 



, 6. When polafs is triturated with ftarch, and a rmall quan- 

 tity of water added, the whole adumes on ftanding the ap- 

 pearance of a femi-tranfparent jelly. On adding water, an 

 opal coloured folution is obtained, from which the ftarch is rea- 

 dily thrown down by an acid. When muriatic acid is em- 

 ployed, a peculiar aromatic odour is exhaled. 



When the infufion of galls is dropt into the folution of ftarch 

 in potafs, a yellowifti white precipitate appears, but is imme- 

 diately re-diflblved, and the liquid remains opake and of a 

 dark brown colour. On adding muriatic acid, a copious pre- 

 cipitate falls, refembling the compound of ftarch and tan. — 

 Nitric acid occafions no precipitate, neither does ammonia. 



The decoction of ftarch is neither altered by potath, carbo- 

 nate of potafti, nor ammonia. 



7. Sulphuric acid diffolves ftarch, and abundance of char- Treatment of 



coal is precipitated. Diluted fulphuric acid, when aflifted by ^^'^^ '^'g'jj^ 



heat, diftblves it without decompofition. Sulphureous acid tion. Separation 



has no effea upon it. >y ^^'^'' The 



I-.M , 1 .. • • 1 /- o 1 n , . , - 1 . infufion of ftarch 



Diluted nitric acid nrft reduces ftarch to powder, and then not affeded by 



difTolves it, with the exception of feme waxy matter, which ^'^^^'"•. 



fwims on the furface. During the folution, fome nitrous gas by the ancient 



is exhaled. mineral acids. 



Strong muriatic acid diflblves ftarch flowly, and without ef-^^^"°°*^"** 

 fervefcence. When the ftarch does not exceed ^ of the 

 acid, the folution is colourlefs and tranfparent, but if we con- 

 tinue to add ftarch, a brown colour foon appears, and the acid 

 lofesa portion of its liquidity. Its peculiar fm ell isdeftroyed, 

 and replaced by the odour which diftinguiflies corn mills. 



Acetic acid does not diftblve ftarch. 



8. Alcohol feparates ftarch in part from its deco6lion. Potafti Expenments 

 <li(rolved in alcohol occafions a copious white precipitatCj^* '^ **' 

 which is re-diftblved on adding a fufficient quantity of water. 

 Alcohol digefted on fulphuret of potafs, occafions a flaky 

 precipitate in the deco6tion of ftarch; this precipitate has 

 fometimes an orange colour. 



Such are the properties of common ftarch: the ftarch ofstarch of pepper 

 pepper poflefles them, excepting only that the colour of its '^^^ 'he preceding 

 precipitates is peculiarly modified by the other Ingredients offsTni7e?to an 

 pepper, from which it is not poflible to free the ftarch com-^^ inthepepper- 

 pletely. <=°'^"- 



A very confiderable portion of the pepper-corn feenis to 

 x2onfift pf ftarch, chiefly united to the oil of pepper. When a 



pepper- 



