c acid"
determinations are practically meaningless. This compound is of so
doubtful a composition and physiological action, and the methods
employed for its determination are so indefinite as to
interpretation, as to render valueless any attempts at comparison
of relative percentages. The only accurate analysis which can be
made is that for caffein.

Much advertising emphasis has been placed on the small amount of
caffein extracted by some devices. What is one of the main reasons
for the consumption of coffee? The caffein contained therein, of
course. So that if one device extracts less caffein than another,
that fact alone is nothing in favor of the former. If the consumer
does not want caffein in his drink there are caffein-free coffees
on the market.

[Illustration: FINE-MEAL GRIND UNDER THE MICROSCOPE]

The coffee liquor acts on metals in such a manner as to lower the
quality of the drink, so that metals of any sort, and by all
means, irons, should be avoided as far as possible. Instead,
earthenware or glass, preferably a good grade of the former, should
be employed as far as possible in the construction of coffee-making
devices.

Of the various metals, silver, aluminum, monel metal, and tin (in
the order named) are least attacked by coffee infusions; and
besides these, nickel, copper, and well enameled iron (absolutely
free from pin holes) may be used without much danger of
contamination. Rings for coffee-urn bags should be made of tinned
copper, monel metal, or aluminum. Even if coffee be made in metal
contrivances, the receptacles in which it stands should be made of
earthenware or of glass.

Painstaking care should be given to the preservation of the
coffee-makers in a state of cleanliness, as upon this depends the
value of the brew. Dirt, fine grounds, and fat (which will turn
rancid quickly) should not be allowed to collect on the sides,
bottom, or in angles of the device difficult of access. Nor should
any source of metallic or exterior contamination be allowed to go
uneliminated.

_The Perfect Cup of Coffee_

Lovers of coffee in the United States are in a better position to obtain
an ideal cup of the beverage than those in any other country. While
imports of green coffee are not so carefully guarded as tea imports,
there is