CHICORY IN COFFEE. 911 



The quantitative estimation of chicory or of the amount of coffee in 

 mixtures can not be made with certainty, and in all such estimations 

 only an approximate percentage content can be stated. The proportion 

 of chicory in a mixture is usually calculated from the specific gravity 

 of an extract made under definite conditions, comparison being made 

 with a coffee extract prepared under the same conditions. In other 

 methods a comparison is made of the depth of color of infusions under 

 certain standard conditions. 



According to A. H. Allen 1 the following method gives fairly good 

 results : 



A weighed portion of the finely ground sample is boiled with water, filtered, and 

 the residue washed with hot water until the filtrate amounts to 10 cc. per gram of 

 the sample taken. The specific gravity of this extract is then determined and the 

 chicory calculated by the formula. 



c = (1.023 d) 100 

 14.5. 



in which c is the per cent of coffee, d the density of the extract. Allen found the 

 mean density of the 10 per cent decoction of a large number of coffees to be 1.0085, 

 and of chicory under the same conditions, 1.023. 



The presence of cereals or other foreign matter would of course render this method 

 unreliable. 



Prenier 2 states that 



Chicory may bo estimated by sifting a definite weight, approximately 2 grams 

 of the ground mixture ; the powder which passes the sieve is always coffee. The 

 larger grains are macerated with cold water for some hours, then thrown on a piece 

 of stretched cloth and rubbed with a pestle. The chicory will pass through the 

 cloth. The residue left on the cloth is now dried and weighed with the powder. 



This is evidently a very rough method. 



Another method for the estimation of chicory, and as rough as the above, is that 

 of C. Draper. 3 In this method a glass similar in shape to a percolator is employed. 

 The stem is graduated and is sealed at the lower end. This apparatus is partly 

 filled with cold water, and a definite volume of the ground sample is slowly dis- 

 tributed upon its surface. The chicory sinks to the bottom of the water and its 

 depth is noted in the graduated tube. 



The writer has found pure coffee, evidently overroasted, that would 

 sink in water. Other writers have also found coffee that would sink, 

 after a few minutes, in water. In case the adulterant has been treated 

 with a fat, it would be liable to float instead of falling to the bottom of 

 the apparatus. Chicory is often so treated. 



The cells, milk vessels, etc., are well illustrated in the Plate XLV. The 

 milk vessels, vasa lacticentia, should be carefully studied, since their 

 peculiarities will usually serve to distinguish chicory from other roots 

 liable to be employed as adulterants. 



Mangoldwurzel. This is a root much used abroad for cattle feeding. 



1 Chemical examination of coffee. Chem. News, 29, 129, 140, 167, 189, 221. Op. cit. 

 30, 2. 



2 Journ. Pharm. Chim. [5] 1, 222-224; Jouru. of the Chem. Soc. 1880, 514. 

 3 Philos. Mag. 38, No. 228, 104; Zeitsch. f. anal. Chem. 7, 388. 



