27 
appeared to have properties somewhat like those of the alkaloid. 
Caffeine, if not the same alkaloid, was considered to have the same 
properties as Theine. Coffee contained less than one per cent. of 
Caffeine, and was, therefore, only half the strength of Tea, but as it 
was Customary to use more coffee than tea it was probable that a cup 
of coffee and tea contained equal quantities of the alkaloid. Caféerc 
Acid was an astringent acid similar to the Tannic Acid of tea, but 
still differing in some particulars. The peculiar odour of roasted 
coffee was supposed to be derived from this substance. 
Besides chicory, first employed to add flavour to coffee, the following 
articles have been detected in adulteration :—Roasted grain, scorched 
peas and beans, roasted carrots, mangold wurtzel, rye, acorns, mahogany 
sawdust, exhausted tan, and baked horses’ livers. 80 tons of coffina, 
consisting of the roasted seeds of some leguminous plant, were offered 
for sale by a Scotch house at £12 per ton, or about 134d. per Ib., and 
the same house offered 500 tons of foreign acorns at £5 aton. The 
addition of some of these articles necessitated the addition of another 
substance called black jack, or burnt sugar, sold in canisters at Is. per 
_ Ib., to bring up the colour. Venetian red and reddle had been used for 
the same purpose. If coffee was suspected of being adulterated by 
chicory, a pinch of the suspected coffee should be placed on a glass slip, 
moistened with water,.and allowed to swell ; it should then be torn to 
pieces with needles, and the structure examined under a }-inch 
objective. Coffee was not easily torn to pieces, and the cells were 
firmly bound together, but chicory was very easily torn to pieces; the 
cells were very easily separated ; and some of the large characteristic 
dotted ducts of which there were so many in chicory and none at all 
____ in coffee would soon be detected. 
Cocoa, derived from the seeds of the Theobroma cacao, like 
_ coffee, required roasting before being used. When roasted it 
contained a Volatile Oil, an Alkaloid, an Astringent Bitter Prin- 
ciple, and a Fixed Oil. Volatile Oil was developed during the 
process of roasting, and formed the aroma of cocoa. It had 
probably the same action as that of tea, but it existed in cocoa in a 
much smaller quantity. Zhe Alkaloid Theobromine was very similar 
_ to Theine, but contained more nitrogen. Theine could, however, be 
prepared from it. Cocoa-nibs contained two per cent. of it, and the 
husk also contained a small quantity. Zhe Bitter and Astringent 
Principles were probably distinct: the bitterness was greater than 
_ that of coffee, but the astringency less than in either tea or coffee. 
The Solid Oil, called Butter of Cocoa, was a hard substance, melting 
easily at moderate temperature, of an agreeable flavour, and not apt 
