30 THE ANALYST. ON CAPER TEA. BY CHARLES ESTCOURT, F.I.C. (Read at the Meeting, Jawuary 4, 1899.) IN the early days of the Food Adulteration Act it was found that tea of all kinds was largely adulterated. Caper tea especially was found to show evidence of gross fraud on the part of the Chinese growers, and as this kind of tea was much used in the North, and especially in Lancashire, I then examined a large number of samples, the analyses of which demonstrated that this tea, as then sold, contained quartz and magnetic iron or0 nodules in quantities varying from 1 per cent. up to as much as 35 per cent. Other analysts also turned their attention to caper tea, the result being that gross adulteration was practically stamped out, as shown by the very few cases of caper tea certified by public analysts as adulterated since 1875.Out of a large number of samples of caper tea analysed in my laboratory from 1876 to 1897, only one contained more than 1 per cent. of mineral impurity. Mr. G. W. Wigner, in 1875, analysed a, number of samples of caper tea drawn from bond. The lowest total ash that he found was 5.75 per cent., and the highest 7-02 per cent. The ash insoluble in hydrochloric acid varied from 0.70 per cent. to 1.67 per cent. In seven out of the nine cases which he records the ash insoluble in hydrochloric acid was less than 1 per cent. Dr. Bell, in 1881, in two samples of caper tea from bond, found that the total ash (calculated on the dry tea) was 6.38 and 6.63 per cent., and the ash insoluble in hydrochloric acid 0.68 and 0-93 per cent.In 1882 Mr. Carter Bell pub- lished in the ANALYST the results of analyses of seventeen samples of caper tea pur- chased in Salford. The total ash of nine of these was less than 7 per cent., in only three cases exceeded 7.5 per pent., and in only one case exceeded 8 per cent. Dr. Bell, the late Principal of the Inland Revenue Laboratory, in his book on ‘‘ The Chemistry of Foods,” says, in reviewing his analyses of genuine imported teas,THE -ANALYST. $i .. the percentage of ash in no case, except one, . . . reaches 8 per cent. ..... on the dried tea. This last ash, when calculated on the original undried sample, is equivalent to 7.7 per cent. With‘ regard to mineral adulterants, Dr. BeU says, speaking of tea? generally: (‘ If the insoluble ash exceeds much more than 1 per cent., there is evidence of the addition of either sand, quartz, or other earthy impurities.” On August 24, 1898, I certified a caper tea as containing “ 2.25 per cent, “of sand and ferruginous earth.” At the hearing of the summons, the magistrates, without my analysis being questioned, sent the third portion of the sample to Somerset House.The following certificate (which, it will be observed, is not signed by either the Principal or Deputy Principal), was in due course received : ‘‘ GOVERNMENT LABORATORY, L 6 Clement’s Inn Passage, “ Strand, London, W.C. The sample of caper tea marked 532, and referred to in your letter of the We hereby 7th instant, was received here on the following day securely sealed. certify that we have analysed the tea with the following results : Total mineral matter ...... ... ... 7-50 per cent. Mineral matter soluble in water ... ... ... 2.36 ,, ,, in acid ... ... 3-12 ,, Silica (less sand) ... ... ... ... ... 1.38 ,, Sand ... ... ... ... ... ... 0.64 ,, ... 9 , ( 4 With thsview of ascertaining how far the sample in question differs from caper tea now met with in commerce, and of fair commercial quality, we have procured a number of authentic samples of such teas out of bond. On analysis they furnish the following results : Total mineral matter ... 6-74 7.90 7.26 7.20 6.44 7.08 8.00 Soluble in water ... 2.58 2.38 2.30 2-54 2-14 2.46 2.30 Soluble in acid .. ... 2-98 2.84 2.90 2.88 3.08 2.14 4-06 Silica (less sand) ... 1-04 0.32 1.76 1.40 1.06 1-26 1-08 Sand ... ...... 0.14 2-36 0.30 0.38 0.16 1-22 0-56 “ It is evident that the amount of foreign mineral matter in the case of the sample referred to us is not higher than that which may be present in genuine caper teas. We are of opinion, therefore, that the small proportion of extraneous matter present has become uuavoidably mixed in the process of collection and preparation. Per Cent. A. B. C. D. E, F. G. 6‘ As witness our hands this twenty-first day of September, 1898. (( (Signed) “G. LEWIN. “ H. W. DAVIES. ‘‘ THE CLERK TO THE MAGISTI:ATES, ( 6 City Police Court, Manchester.” The summons was dismissed. It will be seen that in the certificate the whole question of what genuine caper tea is, is begged. Samples of tea are taken out of bond and are assumed to be authentic, or (as in the term used lower down in the Somerset House certificate) genuine.33 THE ANALYST.These teas, as compared with those imported in 1875, appear to me to begelruine only inasmuch as they have not been stopped by the Customs, but have been, im- properly, allowed to go into consumption. The proportion of mineral matter insoluble in hydrochloric acid-not stated as a separate item in the official analyses, but calou- lated by deducting the water-soluble and acid-soluble ash from the total-would be as follows : Mineral matter insoluble in A. B. C. D. E. F. G. hydrochloric acid ... 1.18 2.68 2.06 1-78 1-22 2.48 1-64 Deduced in the same way, the ash insoluble in hydrochloric acid found at the Government Laboratory in the third portion of my sample was 2.02 per cent.I t will be seen that in these teas, taken from bond, in three cases the ash insoluble in hydro- chloric acid exceeded 2 per cent., being in one case 2-68 per cent., and in another 2-48 per cent.; whereas Dr. Bell, the former Principal of the Inland Revenue Laboratory, laid down the dictum that if the insoluble ash much exceeded 1 per cent,, there was evidence of the addition of either sand, quartz, or other earthy im- purities. In my sample I found nodules of quartz rolled up in the leaves, and there- fore cannot consider that the quartz had been, as is suggested in the certificate from the I t appears desirable that public analysts should be aware of the fact that the limit of earthy impurity fixed by Dr. Bell is no longer adopted at the Inland Revenue Laboratory, and that, apparently, any sample of caper tea containing not more than 2.68 per cent.of ash insoluble in hydrochloric acid is to be regarded as genuine. Attention may also be directed to the proportion of ash soluble in water in caper tea. Mr. Wiper, in 1875, found the proportion of ash soluble in water to vary from 2.64 to 3.66 per cent. in caper tea, the average of nine samples showing 3.07 per cent. In Dr. Beus two m p l e s , anslysed in 1881, the proportion of ash soluble in water, on the dry tea, were S.21 and 3-47 per cent., eqaivdent to 2-98 and 3-23 per oent. in the moist tea. Sinee the sample which gave rise to this paper contained, according to the analysis made in the Government Laboratory, only 2.36 per cent. of mineral matter soluble in water, it might, on the basis of the foregoing figures, be reltsonably regarded as containing exhausted leaves. But the figures found for soluble aeh in the seven samples quoted in the report from the Government Laboratory as authentic samples of mper tea out of bond range from 2.58 down to 2.14 per cent. ; and if these figures are to be accepted as fixing a standard of genuineness in the matter of the admixture of exhausted leaves, the limit of 3 per cent. virtually adopted by Dr. Bell presumably also disappears. overnment Laboratory, unavoidably mixed with the tea.