128 



smells pleasantly, tastes bitter and warming, becomes thicker by- 

 age, afterwards solid and darker, dissolves readily in alcohol and 

 ether. Contains about 10°/^, of volatile oil and two resins, the 

 one of which dissolves readily in cold alcohol, the other sparingly. 

 Some kinds also contain gum. 



MecOIliC Acid = Cu H 4 O14 + 6 HO. As yet only found in 

 opium. Mix the alcoholic solution of opium with a solution of 

 chloride of baryum, and decompose the precipitate of Meconate of 

 baryta with sulphiii'ic acid. It crystallizes in colourless, mica-like 

 laminae, is inodorous, of acid taste, cooling afterwards a little bitter ; 

 loses at 120° all its water of crystallisation; fuses at 150 to 200° 

 and becomes decomposed, yielding a new acid (pyromeconic acid 

 r:Cio H3 O5 ); dissolves moderately in water, readily in alcohol; 

 the aqueous solution is decomposed on boiling under formation of 

 carbonic acid and another new acid (comenic acidzzCi2 H4 Oio). 

 Salts of oxyd of ii'on impart to Meconic acid a vividly red colour. 



Mec01iill=C2o Hio Os. Indifferent substance of opium (the 

 hardened milky juice of the gi-een capsules of Papaver somniferum). 

 Precipitate the extract, obtained by maceration -with water, with 

 ammonia; filter, evaporate the liquid to a syrup consistence and 

 leave to stand cold for a few weeks ; press the brown crystals thus 

 obtained, boil with alcohol of 36° B., concentrate the solution, 

 crystallise what has formed first in boiling water with aid of animal 

 charcoal, next in hot alcohol. — Colourless needles, inodoi'ous ; of no 

 perceptible taste at first, aftei*wards acrid or bitter. Meconin fuses 

 at 90°, distils at 155° unaltered; dissolves in 700 parts cold and in 

 20 parts boiling water, in alcohol, ether, acetic acid and volatile oils. 



]!Ielaiiii»yrit=DuLEiT. 



MelC7iitO.S6=:Ci2 Hii On. Peculiar sweet substance of the 

 manna of Briangon, effiising from the stem of Pinus Larix. Extract 

 the above manna with boiling water, evaporate the extract to a 

 syi-up consistence and keep in a cold place. The Melezitose then 

 forms slowly and has to be recrystallised in alcohol. — Minute, short, 

 microscopic crystals, constituting a white mealy poAvder about as 

 sweet as grape-sugar; effloresce readily at the air, lose in heating about 

 4 })er cent, of water, fuse below 140° without further change; are 

 decomposed at 200°, dissolve readily in water, scarcely in cold, 

 slightly in boiling alcohol, not in ether; become carbonised by cold 

 concentrated sulphuric acid ; yield with nitric acid oxalic acid, with 

 diluted sTÜphuric acid on heating grape-sugar (more readily than 

 trehalose, but less so than cane-sugar). Melezitose generally 

 undergoes with beer-yeast a slow alcoholic fermentation; is not 

 altered by heating with alkalies or alkaline tartarate of cooper; is 

 precipitable by ammoniacal acetate of lead. 



Melm=:RuTiN. 



