430 MECONIC ACID. 



3. Lichenstearic acid, C 14 H 24 3 . Together with cetraric 

 acid in Iceland moss. Fine, shiny crystalline laminae; 

 insoluble in water, easily soluble in alcohol and ether. 



4. Vulpic add, C 19 H 14 5 . In the lichens, Cetraria vul- 

 pina, and a variety of Parmelia parietina, from which 

 it can be extracted by lukewarm water and milk of 

 lime ; and then reprecipitated by hydrochloric acid. 

 Yellow crystals, very similar to usnic acid ; insoluble 

 in water, but slightly soluble in alcohol, more readily 

 in ether. By boiling with barium hydroxide, it is 

 decomposed into methyl alcohol, oxalic acid, and alpha- 

 toluic acid (p. 340); by boiling with dilute caustic 

 potassa, into methyl alcohol, carbonic acid, and oxa- 

 tolylic acid, C 16 H 16 3 . The latter crystallizes in color- 

 less, four-sided columns, fusing at 154 ; insoluble in 

 water ; in alcohol and ether more easily soluble ; and 

 is resolved, by continued boiling with concentrated 

 potassa-ley, into oxalic acid and toluene. 



5. Meconic acid, C 7 H 4 7 (= C 4 j ^ OH) 3 ) In the 

 milky juice of the poppy (Papaver somniferum) and the 

 opium prepared from this. The crude calcium meco- 

 nate, obtained in the preparation of morphine, is re- 

 peatedly treated with dilute, hot hydrochloric acid ; 

 the acid, which crystallizes out in a still impure con- 

 dition on cooling, is dissolved in dilute, warm am- 

 monia; the salt recrystallized several times from hot 

 water, and finally the acid precipitated from the hot 

 solution of the salt by means of hydrochloric acid. 



Crystallizes from water in colorless, shiny laminae 

 or prisms, with three molecules of water of crystalliza- 

 tion. Of a weak, sour taste ; difficultly soluble in cold 

 water, more easily in hot water and alcohol. Colors 

 solutions of ferric salts a deep red. Tribasic acid. 

 When treated with sodium-amalgam, it yields an 

 amorphous, deliquescent acid, difficultly soluble in 

 alcohol, hydromeconic acid, C 7 H 10 7 . Heated to 220, 

 or boiled for a long time with water, particularly with 

 dilute hydrochloric acid, meconic acid is resolved into 



