168 COlTEE. 



cause it to float. In most instances, also, part of the coffee sub- 

 sides with the chicory and part of the latter remains on the sur- 

 face with the coffee, and after' a lapse of a short time both coffee 

 aud chicory fall to the bottom. 



3, If the cold water to which a portion of ground coffee has 

 been added quickly becomes deeply colored, it is an evidence of 

 the presence of some roasted vegetable substance or burnt sugar ; 

 for, when coffee only is added to water, the liquid becomes 

 scarcely colored for some time. 



4. Make a boiling aqueous solution with the coffee ; if it be 

 an infusion of pure coffee, it will be' found thin and- limpid ; if,, 

 on the contrary, it be adulterated with any substance containing 

 much gum and starch (as rye, peasj etc.), it will be thick and 

 mucilaginous. 



Lastly, spread out, on a piece of glass, a little ground coffee 

 and moisten it with a few drops of water ; if you are enabled to 

 pick out, by means of a needle, minute pieces of a substance of a 

 soft consistence, the coffee is doubtless adulterated ; for the parti- 

 cles of the coffee-seed are hard and resisting, and do not become 

 soft even after prolonged immersion in water. 



These simple means will usually suflBce to detect the general 

 fact of adulteration. To determine the character of the adulter- 

 ants used, we must appeal to science ; and for this purpose, as 

 for so many others, the microscope proves the most powerful 

 auxiliary and most reliable detective. 



Viewed under the magnifying-glass, the component fibres and 

 elementary structures of the different ground substances present 

 peculiarities and characters that enable an experienced observer 

 to identify, beyond a doubt, the particular adulterant or adulter- 

 ants employed. 



Chicory is distinguished by the size, form, and ready separa- 

 tion of the component cells of the root, as well as by the presence 

 of an abundance of spiral vessels of the dotted form. Koasted 

 cereals, beans, etc., by the respective size, form, and other charac- 

 ters of the starch granules of which the grains are principally 

 composed. Figure 1 (Plate I.) gives the appearance, magnified 

 to one hundred and forty diameters, of a fragment of roasted 

 coffee ; Fig. 2 (Plate I.), that of a fragment of roasted chicory ; 



