Show of ten tea 13 sometimes with the leaves of other plants as for instance aloe ash hawthorn etc but by a careful examination adul te rations can be easily fauntl out genuine tea leaves when moistened with hot water and opened and alion examined by alic microscope show a very characteristic te venation once seen this character will not bo easily forgotten acis adulterated in other ways besides the admixture of foreign leaves y il the leaves aio often faced or artificially colored with prussian blue and turmeric or indigo and talc tea is often faced willi plumbago 2 alic leaves arc sometimes mixed with sand and other mineral substances all of these bodies can bo by and chemical analysis in alic ordinary way there is still another method in which this leaf is tendered not genuine clial is tins practice of selling llie tea more or less exhausted A pretty fair judgment as to adulteration of a sample of tea can be armed at by a simple process i is based on the extraction of the contained in tea and ascertaining the of alicino extracted from a known of tea tea contains from a half to fc per cent of the way to proceed in this new of extraction is to weigh out about grammes of alic sample of tea and boil with two laitres litres of distilled water in a glass beaker allow alic infusion to boil for five minutes then add to alic infusion a small ouan tit of gliss reduced to a fine powder and mig nesie oxide keep this mixture in strong ebullition for about twenty or twenty five at alio same time occasionally stirring with a glas gla s lod again add cc of water and boil for fifteen minutes longer the aqueous is now to bo evaporated very carefully to complete dryness the residue left on evaporation is to be treated three or tour times willi rectified ethylic colier by means ol 01 s three or four treatments with colier generally to remote all the lat la t portion of alio washings when evaporated geould leave no residue these ethereal solutions aro to bo gently heated and then allowed to evaporate in a dili of known weight the solid ie Is alic pure alkaloid theine the dish and its contents are naw weighed thu weight of alio dish and alio ll icino minus the of thu dish alone gives of course thaw aliu from this the percentage of theine in alic original of tea can be ascertained by means of proportion jt tho percentage is less glnn a liala per cent you kiy conclude conc ludo that the sample lias been cither adulterated with foreign leaves which can easily be recognized by their botanical structures under the microscope or the leaves hao been exhausted science gossip |