888 FOODS AND FOOD ADULTERANTS. 
among the samples which he submitted to analysis, 50-cent 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’ 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 theine 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 teas of the season of 1890. 
[Tea dried at 100° C.] 
Total 
amount of Products 
Num- Products | Extract- |theine, tan-| Theine, | Tannin, joffermen- 
ber of | Water. | Theine. | Tannin. joffermen-| ive sub- | nin,and | percent | per cent | tation, 
tea. tation. | stances. |products of}  A.* UARSeS per cent 
fermenta- A.* 
tion.* 
il 7.44 2.14 9. 44 1. 80 33. 43 13. 38 16. 00 70. 5d 13. 45 
2 Tot) 2.50 9. 87 | HAG 33. 33 13. 98 17.89 70. 60 | 11.51 
3 8.29 2.53 9.27 | 1. 68 32. 11 13. 48 18. 78 68. 76 12. 46 
AN Pacvegeret ee sae 2.68 10. 05 1. 44 37. 26 14. 17 18. 92° | 70. 92 10.16 
5 7.97 2. 66 9.77 OD 34. 55 13. 98 19. 03 | 69. 89 11. 08 
6 8.16 2. 65 9. 76 | 1.45 31. 20 13. 86 | 19.13 | 70. 41 10. 46 
7 7. 66 2.72 9.59 1.78 30. 70 14, 09 19.21 68.06 12. 63 
8 7.90 D238 je iteecadlLay Che Sell eo ASS eyed Oe hie eee eee ee eee |: by Rs Pas 
9 7.91 | DA <} Ofte RA a ae ee ee ee ee aS Ae ee eo Ieee ae real ors Ilo G oss 68 
AUD et te 2.91 10. 38 1.52 34. 88 14, $1 19. 65 70. 09 10. 26 
jal 7.60 | 3. 00 10. 55 NG, 34. 00 15522 19. 79 69. 31 10. 90 
*Total amount of theine, tannin, and products of fermentation is represented by A for brevity. 
1Examination of China Teas, P. Doorkovitch, Jour. anal. and appl. Chem., 5, 6, 345. 
