7(J ON PEPPER. 



Ihera in a flafk with Hve ounces of water, and then added |6z. 

 menfare of the infufion of galls. On cooling, a copious pre- 

 cipitate fell, and the liquid remained only faintly coloured. 

 The precipitate dried in a fteam heat weighed 31 grains, and 

 iht refidual liquid left 11 grains of refidue. The whole 

 amouiited to 42 grains; which is very nearly equal to the 24« 

 grains of i\?,rch and 17 of tan employed; the compound in this 

 cafe confilU of 



58. 5 ftarch, or nearly 3 (larch 



41.5 tan » - . - 2 tan 



100,0 5 



The compound of ftarch and tan is of a light brownifti yel- 

 low colour, femi-tranfparent and brittle^ and has a good deal 

 of refemblance to common farcocoll. Its tafte is aHringent ; 

 it feels glutinous between the teeth, like gum. It is very im- 

 perfectly foluble in cold water, but hot water difiblves it abun- 

 dantly. Alcohol digefted on it acquires a brown colour; but 

 is incapable of feparating the whole of the tan from the ftarch. 

 When heated, it froths, fwells and melts, and then burns with 

 a clear flame, leaving like ftarch a fmall portion of white aflies 

 behind it. 

 Infufion of ftarch 5. To afcertain the effeft'of the earths and metallic oxides 

 toeatoijwith ^^ flarch, an infution of it was formed by triturating 24 grains 

 of ftarch with 4f ounces of water, and then boiling the miX' 

 ture for fome time. The decodion thus formed, is nearly 

 tranfparent, and of a flight opal colour. When fet afide, at 

 leaft a month elapfes before the ftarch begins to fubfide. 



When lime water is mixed with this decoction, no change 

 is produced; neither is any perceptible alteration occafioned 

 by ftronti^ water; but barytes water throws down a copious 

 white flaky precipitate. This precipitate is re-difl>)lved by 

 muriatic acid, but appears again on ftanding unlefs a confider- 

 able excefs of acid has been added. Vet muriate of barytes 

 occafions no change in the decodlion of ftarch. 

 —with metallic No metallic fait feems to have the effedl of throwing down 

 felts : no cffca. ^^^^^ ^^^^ j^^ jecoaion. The following were tried : 

 Nitro-muriate of gold, platinum; 

 Nitrate of filver, mercury, lead; 

 Muriate of tin, acelite of lead; 

 Salts of copper, iron, zinc; 

 Ammoniated nickel and cobalt. 



6. When 



