fiuoke, which eafily alJaches to ihe ehimney : this combufllon 

 always takes place, although the crucible be taken out of the 



A whitlQi refidue is left, which is very alkaline and partly leaving an alka- 

 fbluble in water. Re-agents demonftrate the prefenee ©f ''"^ "^'^"'* 

 fulphate and muriate of poladi. 



That part which water could not take up, on being put Experiments oft 

 into muriatic acid was diffolved with fome efTervefcence. refidue. 



This liquid is copioufly precipitated by the oxalate of am- 

 monia j pruffiate of potafli gives a blue precipitate. That 

 produced by ammonia is of a party confidence, partly foluble 

 in cauftic potafh : whence maybe inferred that the refidue. It contains fo* 

 independent of the falts foluble by water, is compofed of the [^ll^^l^^f 

 carbojiates of lime and of alumine, with a fmall portion of lime, and alu- 

 l|.0lj^ mine and iron. 



Water has very little influence on birdlime. On boiling. Water has little 

 the matter does not completely difTolve, but acquires merely ^|^°" °" ^"'^' 

 a fmall increafe of fluidity, which it lofes in cooling, and 

 fefumes its primitive confiftency. 



This water obtains no colour; its flavour Is at firfl infipld, 

 afterwards four, and it reddens tindure of turnfole. 



Evaporated to the confiftency of a fyrup, it becomes co,. 

 loured, with a mucilaginous appearance, which may be fepa- 

 r^ted by alcohol. 



The action of water, therefore, is confined to Ijie folution It takesupfanae 

 of a mucilaginous fubftance, with a fmall portion of the ex- ">*<^^^^6^» 

 tra6live matter. 



It is not thus with cauftic potafh. Its concentrated folu- Cauftic potaflj 

 tion forms at once with birdlime a whitifii magma, which ^j'r'di^'"^^ "'^ ^ 

 turns thrown on evaporation, with a feparation of ammonia, gives out ammo. 



This eompofition is lefs vifcid ; it acquires a great degree"'** 

 of bardnefs by expofure to the air j and its fraell and tafte are 

 iimilar to thofe of foap. 



It is. chiefly foluble in water aiid alcohol, there remaining The compound 

 but a few- vegetable dregs. Thefe folutions are affeded by ^'^3*"^^^^^^"* 

 flrong acids; but thefe kinds of decompofitions prefent no 

 pew phenomena to thofe obtained with a folution of foap. 



Themoft feeble acids foften birdlime, and partly diflblve it; Weakacid« 



when concentrated, they ad in a different manner. i?!i^" ^"l P^'^^Y 



'J ' diflblve bird- 



Sulphuric acid renders it black and charry : by adding pow- lime. 



^ered lime, fo as to form a thick maema, a reparation of ace- s^'iphuric acid 



° ' . chafis It. 



tic 



