ANALYSIS OF COFFEE. 31 



seems to me a much more laborious piece of work than is warranted by the value of the 

 result. If the amount of sugar in a commercial coffee be higher than 2 per cent., the sample 

 must be sophisticated ; if below this limit, it does not certainly follow that the coffee is 

 genuine. It is a very easy matter, and the work of a few minutes only, when the solution as 

 clarified and freed from lead for the estimation of caffeine is used, to set limits to the per- 

 centage of sugar present. For this purpose, I make up the clarified filtrate, above 

 described, to 250 c.c. ; of which I use only 200 c.c. (= 4 grammes coffee) for estimation 

 of caffeine ; and, boiling in a large test tube 2ô c.c. Fehling's solution, diluted with water, 

 I add the whole of the remaining 50 c.c. of clarified extract (= 1 gramme coffee.) 



A few drops of the liquid so treated, should, on filtration, be found to contain dissolved 

 copper, thus shewing less than r25 per cent, glucose in the coffee. If any considerable 

 portion of chicory, or other sugar containing adulterant, be present, the Fehling's solution 

 used will be completely reduced. 



