SOPHISTICATION AND SUBSTITUTION 145 



terial in a solid state or with the sample residue from the evapora- 

 tion of a liquid : 



Procedure: — (Allen) Heat small quantity of the solid or pow- 

 dered material in a white porcelain dish. Cover with a few 

 drops of strong HCl. Add (immediately) a fragment of potassium 

 chlorate. Evaporate to complete dryness on water bath. (If 

 caffeine be present, production of reddish-yellow or pink color is 

 noted.) Cool. Treat residue with very little ammonia water, 

 apphed on the point of a stirring rod. 



Test: — If positive, purple color (murexion). 



(b) For Quantitative Extraction of Caffeine, see "Allen's 

 Modification of Stahlschmidt's Method" under section on "Chem- 

 istry of Coffee." 



C. Microscopic Examination: 



1. With hand lense (See Plate 2, Genus Coffea: Fruit Mor- 

 phology) : 



(a) Coifee-beans possess a characteristic shape with a very char- 

 acteristic cleft on the ventral surface which is absent on many 

 poorly manufactured beans. 



(b) A portion of the parchment investment always remains 

 adhering closely in the cleft of genuine beans. The membrane 

 is always absent in factitious beans although sometimes the cleft 

 is filled with fine sawdust (powder). 



(c) Cross-section through the center of a bean shows a charac- 

 teristic furrow with a fragment of the parchment; and the line 

 of the embryo in the endosperm. 



(d) Cross-section through the germ end shows the furrow; the 

 line of the embryo and a portion of the embryo (through cotyle- 

 dons or radicle). 



(e) Longitudinal section, taken parallel to and slightly to one 

 side of this cleft, shows the characteristic long line of the embryo 

 and the germ at one end. 



2. With low-power microscope: 

 (a) Raw bean tissue examination: 



Preparation of Bean: — Soak raw beans in water several hours 

 or in equal parts of alcohol and glycerin for i to 2 days. 



Preparation of seed-coat: — Cut a bean lengthwise through the 



