30 



compounds are all soluble in water, and have, when moist, the 

 odour of fresh butter. Butyric acid is not unfrequently con- 

 taminated by acetic acid, and may be recognised by the formation 

 of acetic ether, when heated with sulphuric acid and alcohol, but 

 the exact separation of the two acids from each other is very 

 difficult and has as yet not been cai'ried out to satisfaction. 



Buxin= Bebirin. 



CaCJlO Fslt. Obtained by pressing the prepared beans of 

 Theobroma Cacao. White or yellowish- white, as hard as mutton 

 tallow, of 0'90 specific gravity, of a faint cacao-like odour and 

 mild taste, fuses at 30°, contains olein, stearin and a little 

 palmitin. 



CafFeic Acid or Coffea Tannic Acid=Ci4 Hs O7. In the 



seeds and leaves of Coffea Arabica, in the root of Chioccoca 

 racemosa, in the leaves of Ilex Paraguayensis. Exhaust the 

 pulverised coffee-seeds with ether, boil the remaining powder 

 with alcohol of 40%, mix the alcoholic filtrate with twice its 

 volume of water, remove the precipitated fatty flocks, boil, add 

 solution of acetate of lead and boil for a few moments, in order 

 to make the precipitate less voluminous and more easy to collect. 

 Wash the precipitate with diluted alcohol, decompose under water 

 with sulphuret of hydrogen and evaporate the filtrate on the 

 water bath. Brittle substance, friable to a yellowish powder, of 

 faintly acid and somewhat astringent taste, dissolves readily in 

 water and in alcohol of any strength, little in ether, imparts a 

 green colour to chloride of iron. Its compounds with lime and 

 baryta are yellow and turn green at the atmosphere (by the 

 formation of a new acid called Viridic acid:=Ci4 Hß O7). 



Calfein=Ci6 Hio N4 O4 4- 2 HO. In the fruit and leaves of 

 Coffea Arabica, in the leaves of Thea Chinensis, of Ilex 

 Paraguayensis, in the fruit of Paullinia sorbilis, of Lunanea 

 Bichi. Its preparation from the coffee-seeds is done in the 

 following way. Mix five parts seeds, ground as finely as pos- 

 sible, with one part hydrate of lime, digest with 25 parts alcohol 

 of 80%, filter and mix with alcohol, distil off" the alcohol and 

 leave the remnant to become cold, remove the oil, evaporate 

 and purify the crystals by recrystallisiiig. It forms long, flexible, 

 white, silky needles without odour and of faintly bitter taste, 

 loses the water of crystallisation at 100°, fuses at 177°, sublimates 

 at 384° undecomposed (according to more recent observations : 

 fusing at 224° to 228° and sublimating already at 177°); dissolves 

 iu about 60 parts water of 20°, in 9 '5 parts boiling water, in 21 

 j)arts alcohol of 0.825, in 545 parts ether, in 9 parts chlorofonn ; 

 the solutions liave a neutral reaction. It is also dissolved by volatile 



