Food Adulteration and Its Detection / With photomicrographic plates and a bibliographical appendix

by Jesse P. Battershall

Extract.

Range	20 to 25 per cent.	25 to 30 per cent.	30 to 35 per cent.	35 to 40 per cent.
Number	21	151	499	179
Per cent.	2·47	17·76	58·70	21·05

The following tabulation exhibits the results obtained by the examination of various grades of Formosa, Congou, Young Hyson, Gunpowder, and Japan tea, made, under the supervision of the writer, by Dr. J. F. Davis.

It will be noticed, if the same varieties of tea be compared, that, with some exceptions, their commercial value is directly proportional to the percentages of soluble ash, extract, tannin, and theine contained.

Variety.	Formosa Oolong, Choice, 1st Crop.	Formosa Oolong, Superior, 1st Crop.	Formosa Oolong, Choice, 3rd Crop.	Formosa Oolong, Superior, 3rd Crop.	Congou, Choicest.	Congou, Medium.	Congou, Common.
	c.	c.	c.	c.	c.	c.	c.
Price per lb. (wholesale).	70	28	55	24	65 to 70	24	14
	p.c.	p.c.	p.c.	p.c.	p.c.	p.c.	p.c.
Total ash	6·50	5·96	5·80	6·34	6·22	6·36	6·58
Ash soluble in water.	3·60	2·86	3·12	3·60	3·56	3·00	2·88
Ash insoluble in water.	2·90	3·10	2·68	2·74	2·66	3·36	3·70
Ash insoluble in acids.	0·86	0·94	0·56	0·66	0·56	0·66	1·06
Extract	42·00	37·40	43·20	40·60	34·60	29·60	26·20
Insoluble leaf	54·90	59·55	52·70	56·55	60·75	64·80	68·75
Tannin	18·66	16·31	18·00	16·05	14·87	13·70	12·26
Theine	3·46	2·20	2·26	1·39	3·29	2·23	2·35

Variety.	First Young Hyson, Regular Moyune.	First Young Hyson, Plain Draw.	Second Young Hyson, Moyune.	Third Young Hyson, Plain Draw.	Choice Gunpowder.	Third Gunpowder.
	c.	c.	c.	c.		c.
Price per lb. (wholesale).	28 to 30	25	17 to 18	14	35	23
	p.c.	p.c.	p.c.	p.c.	p.c.	p.c.
Total ash	6·26	5·86	5·84	6·20	5·76	5·50
Ash soluble in water.	3·60	3·28	3·36	3·34	3·26	3·14
Ash insoluble in water.	2·66	2·58	2·48	2·86	2·50	2·36
Ash insoluble in acids.	0·64	0·58	0·50	0·52	0·54	0·52
Extract	40·60	41·00	39·80	30·40	39·60	36·00
Insoluble leaf	55·50	57·70	57·15	61·95	56·70	57·90
Tannin	18·00	19·96	18·53	16·99	20·09	17·87
Theine	2·26	2·30	1·16	1·08	1·78	1·42

Variety.	Uncoloured Japan, Choicest, First Picking.	Coloured Japan, Good Medium First Picking.	Coloured Japan, Good Medium, Third Picking	Japan Dust
				Coloured, Fine.	Uncoloured, Common.
	c.	c.	c.	c.	c.
Price per lb. (wholesale).	30	22	19	9	6
	p.c.	p.c.	p.c.	p.c.	p.c.
Total ash	5·44	6·06	6·50	9·74	6·66
Ash soluble in water.	3·46	2·84	2·90	1·48	2·78
Ash insoluble in water.	1·98	3·22	3·60	8·26	3·88
Ash insoluble in acids.	0·46	0·78	0·96	3·90	1·46
Extract	39·20	36·40	33·40	31·80	32·80
Insoluble leaf	56·85	57·10	59·90	61·45	60·05
Tannin	21·92	18·27	17·35	15·66	17·74
Theine	1·54	1·66	0·74	0·82	2·43

The following analyses of several kinds of spurious tea, received from the U.S. Consuls at Canton and Nagasaki (Japan), have been made by the author:—