888 



FOODS AND FOOD ADULTERANTS. 



among the samples which he submitted to analysis, 50-eent teas (retail 

 price) containing as much tannin as many of those whose selling price 

 was nearly double this amount. 



An attempt was made in classifying teas to utilize the property which 

 high grades have of quickly giving up a portion of their soluble matter 

 when steeped in water. These experiments were carefully made, the 

 conditions being the same in each case, but unfortunately the results 

 were far from satisfactory. This problem must be left until more 

 thorough studies of the chemistry of teas have been made, and until 

 then we must continue as heretofore to depend upon the skill of the 

 professional tea-taster and the honesty of the dealers in regulating the 

 relative prices. 



Since the above and other remarks on the valuation of teas were 

 written, a Russian chemist 1 has made an interesting series of investi- 

 gations bearing upon this question. 



According to this chemist the quality of the tea depends upon the 

 care with which the fermentation is conducted. The fermentation of 

 the leaves destroys a portion of the tannin, thus decreasing the astrin- 

 gent action of the tea. Mr. Doorkovitch has devised a process for the 

 estimation of the products of the fermentation. In the article cited he 

 presents the table of analyses given below, and on a basis of these 

 analyses makes the following deductions: 



The greater the ratio of theiue to the total amount of tannin and products of fer- 

 mentation, the dearer the tea. The more regular the fermentation, the better 

 the tea. 



The regularity of the fermentation is recognized by the relative amount of prod- 

 ucts of fermentation in tea. 



Analyses of first-crop China leas of Ihe neaxon of 1890. 

 * [Tea dried at 100 C.] 



'Total amount of tlii-me. tannin, and products of fermentation is represented by \ for Invvity. 



K \arni nat ion of China Teas. 1'. Doorkovitch, Jour. anal, and ajipl. Chrin., 5. ti, ;<15. 



