BIRDLIME. 14^^ 



x^cetous acid foflens birdlime and dilTolvcs a certain qiian- Acetous acid 

 . , xi I- • It I -x 1 n • • r -J f^i^ens birdlime, 



♦ itv; the liquor acquires a yellow colour ; its (alie is inlipid. ^^^ 



Carbonate oF potafh produces no precipitate; evaporation 

 gives a refinous refiduum, which cannot, however, be brought 

 to a fiate of perfect drjnefs. 



Certain metallic oxides are eafily reduced on being heated Birdlime re- 

 with birdlime. ''"'f ™=^^'^''= 



oxides. 



Semi-vitreous oxide of lead affumes a grey colour, diflblves. Semi vitreous 

 and forms with the birdlime an emplaftic mafs, f"'"^'^ of lead 



incorporates 



Alcohol at 40 degrees, and boiling, dilfolves birdlime fo with birdlime, 

 long as it is kept hot ; it is clear, and of a tranfparent yellow Boilmg alcohol 



, . . • ' ■ r , •. . diffolves bird. 



colour; but m proportion as the liquor cools, it becomes j,;jj£^ 



turbid. 



A yellow matter may be feparated by filtering, which is and lots fall a 

 much fofter than the original mafs; melts in a moderate heat, ^q",*! pg^."^" **' 

 difFufing a froell analogous to that of wax, of which it feems 

 to poflefs all the quaiilies. 



The filtered liquor is bitter, naufeous, and acid; precipi- retainingarefin^ 

 tating in water, and leaving on evaporation a fubftance fimilar 

 to refin. 



Sulphuric ether may be confidered as the true folvent of Sulphuric ether 

 birdlime: its adion on this fubflance is rapid, firft dividing it» ot biidhme.^**' 

 and then dilTolving it nearly in toio, there remaining only a 

 few vegetable dregs. The liquor acquires a greeniOi yellow 

 colour, and ftrongly reddens turnfole. On adding a liulc Water feparates 

 water the mixture thickens, and the ether fwims on the top; lotion. 

 but if a fufficient quantity of water be poured, in to di.Tolve 

 the ether, a body of oil is formed on the furfac)^, bearii:ig a 

 confiderable analogy to that of linlfeed : this iriay be con- 

 verted, by the affifiance of the femi-vitreous oxide of lead, 

 into an emplaftic mafs. 



By evaporating the folution of birdlime in ether, a greafy Ether by evapo- 

 fubftance is obtained, of a yellow colour, and of ^^^^ ^"^t^efs "g"^" ^^^^^^^^^p 

 of vva^. 



Conclufion, 



From the foregoing obfervations it will be perceived how 



little analogy exitls between birdlime and gluten. 



A fimple comparilbn will be fufficient to defignate the place General proper- 

 ., ,,, ,,, jT ties of biidlim". 



it ought to occupy ^mong vegetable productions. 



Birdlime 



