In comparing with standards, examiners are to test all the teas on these points, namely - for quality, for artificial coloring or facing matter, and other impurity, and for quality of infused leaf. Quality shall be ascertained by drawing, according to the custom of the tea trade, with the weight of a silver half dime to the cup. The quality must be equal to standard, but the flavor may be that of a different district, as long as it is equally fit for consumption. As an illustration, a Teenkai may be equal to a Moyune, but a distinctly smoky or rank Fychow or Wenchow of sour character is not considered equal to the first two mentioned.

In examining Japans and all other green (unfermented) teas, while limiting the comparisons in the matter of infused leaf to the specific standard called for, examiners are advised to admit teas upon the question of quality, in the two kinds above cited, provided that they are equal in the case of Japans to either the pan-fired or the basket-fired standard; in all other greens to either the Gun-powder or the Young Hyson standard.

In order to test the quality of the infused leaf in comparison with the standard, a second drawing should be made of double weight. After pouring off the water, the infused leaf should be taken out so as to exhibit the lower side which rested against the cup. Should the mass show a larger quantity of exhausted or decayed leaf than the standard it affords sufficient evidence to be judged inferior in quality and consequently to be rejected.

To examine for artificial coloring or facing matter, it is advised that the following-described method be used in comparison with the standard, viz.:

Read Color Method.1 - Place two ounces of tea in a sieve 5 or 6 inches in diameter, having 60 meshes to the inch and provided with a top. Sift a small quantity of the dust onto a semiglazed white paper about 8 by 10 inches. The amount of dust placed on the paper should be approximately one grain. To get the requisite amount of dust it is sometimes necessary to rub the leaf gently against the bottom of the sieve, but this must not be done until the sieve has been well shaken over the test paper. The dust thus collected should be poured from the paper into the scales, and after weighing the amount of one grain it is returned to the same paper, and should be well distributed over the surface of the paper. The paper should then be placed on a plain, firm surface, preferably glass or marble, and the dust crushed by pushing over it, with considerable pressure, a flat steel spatula about five inches long. This is done repeatedly, the tea dust being ground almost to a powder and the particles of coloring matter, if any, being thus spread or streaked on the paper, so as to become more apparent. The loose dust should then be brushed off and the paper examined by means of a simple lens magnifying 7 1/2 diameters. In distinguishing these particles and streaks bright light is essential.

1 Modified in harmony with Supreme Court decision T. D. 37637, May 16, 1918.

The crushed leaf in either black or green tea appears in such quantity that there is no chance of mistaking the leaf for artificial coloring or facing material.

This test is performed in comparison with the standard, and if the tea is clearly equal to the standard as regards artificial coloring or facing matter, the operation need not be repeated. If particles of artificial coloring or facing are found in the sample under comparison with the standard, this operation should be repeated a sufficient number of times for the examiner to satisfy himself whether or not the tea contains impurities consisting of artificial coloring or facing matter in excess of the standard. If found to contain artificial coloring or facing matter in excess of the standard, samples should be drawn from packages representing at least 5 percent of the line in question and subjected to the above test to see if a majority of these samples contain artificial coloring or facing matter in excess of the standard.

The above test may be applied to all varieties of tea.

In the case of Japans and all other green (unfermented) teas, in addition to the above white-paper test, repeat the operation in comparison with the respective standard on semiglazed black paper for facings, and if it is not equal to the standard, additional samples should be drawn and tested as provided above in the test on white paper. Should the examination of the sample by the "cup test" double weight, for scum, sediment, etc., or the "Read Test," or both, disclose more impurities than the standard, then a pound sample should be sent to the local appraiser's chemist or to the nearest pure food laboratory of the Department of Agriculture and an analysis made in comparison with the standard to determine whether it contains more impurities than the standard. If the tea in question is found to contain more impurities than the standard, it would properly be rejected as not being equal to the standard in purity.

All extraneous substances are impurities, and the presence of any may be detected in any way found efficient. This black-paper test detects all facings like talc, gypsum, barium sulphate, clay, etc.

Should a tea prove on examination to be inferior to the standard in any one of the requisites - namely, quality, quality of infused leaf, or purity - it would justly be rejected, notwithstanding that it be superior to the standard in some of the qualifications. No consideration shall be given to the appearance or so-called style of the dry leaf.