Anahjsh of Birdlime. 135 



facts we should be led to conclude, that the ashes contain, 

 besides the salts soluble in water, a quantilv uf the carbo- 

 nates of lime and alnmine, with a little iron. 



Water has very little action upon birdiinic. When raised 

 to boiling, the matter does not completely melt; it acquires 

 rather more fluidity, but resumes its former consistence by 

 cooling. The water has no colour ; its taste is nauseous, 

 and then bitter : it reddens the tincture of turnsole. When 

 evaporated to the consistence of syrup it becomes coloured, 

 and assumes a mucilaginous appearance. The admixture of 

 alcohol separates this matter. 



Water, therefore, only dissolves a mucilaginous substance, 

 and a little extractive matter. 



Caustic potash, on the other hand, has a very different 

 action. Its concentrated solution immediately forms with 

 birdlime a whitish magma, which becomes brown by eva- 

 poration : there is at the same time a disengagement of am- 

 monia. 



The compound formed is less viscid : it acquires a greater 

 hardness by exposure to the air : its odour and taste are si- 

 milar to those of soap. 



It is completely soluble in alcohol, with the exception of 

 a few vegetable remains. Tliese solutions become muddy 

 on the addition of the strong acids, and exhibit the other 

 phaenomena which are observed in the solutions of soap. 



The weaker acids soften birdlime, and partly dissolve it : 

 bnt when concentrated they act in a diflerent manner. Sul- 

 phuric acid blackens and chars it : if powdered lime be 

 added so as to form a thick magma, a disengagement of 

 acetic acid and ammonia takes place : there is no doubt 

 that, besides the free acetic acid contained in the birdlime, 

 a new quantity is formed by the action of the sulphuric 

 acid. 



The nitric acid has little action in the cold upon the sub- 

 stance under examination ; but if the temperature be raised 

 it becomes yellow, melts, and as the evaporation proceeds 

 tlie matter swells considerably, and a hard brittle mass re- 

 n)ains. When submitted a second time to the action of the 

 nitric acid, a solution is effected, and a part of this substance 

 I 4 i» 



