ANALYSIS OP COFFEE. 



29 



In the opposite table (Table IV) I have calculated the densities for each increase of 

 5 per cent, in the amount of dry chicory ; and have, in Columns 3 and 4, given the chicory 

 indication corresponding to that density, copied from Blyth's " Manual of Food Analysis " 

 (p. 353), and the amount of error resulting from the interpretation of results obtained, as 

 described above, by the table there published. 



Table V.— Results of analyses of H CoMMEnciAL Coffees, costaininc, no other adiltbrakt than Chicory. 

 The ash, fat, caffeine, tannin and sugar are expressed as percentages on the dry substance. 



Ash. — I have, in most cases, made the estimate of the soluble part of the ash in both 

 of the following ways : — 



1. — By difference : the insoluble portion of the ash, both that in the platinum dish 

 and that on the filter, being ignited and weighed, and the weight obtained subtracted 

 from the weight of total ash. 



2. — Directly : by evaporating to dryness the aqueous filtrate, and igniting the residue 

 so obtained. 



The practical identity of result obtained by each method is shewn in. the case of pure 

 coffees, and mixtures of coffee and chicory, in Tables I and IV. 



These results are in accordance with the statements of the various writers upon the 

 commercial analysis of coffee, inasmuch as they shew that the percentage of soluble ash 

 is lessened by admixture of chicory ; but they entirely fail to corroborate the table given 



