Merck's Pyrogallic Acid

will be found, upon comparison, to be superior in every respect to all other brands on the market. Its distinctive points of superiority are:

1ST.—ABSOLUTE PURITY

2D.—PERFECT CRYSTALLIZATION

3D.—IMMACULATE WHITENESS

4TH.—EXTREME LIGHTNESS

5TH.—MODERATE COST

(Its price is not higher than that of any other make.)

Merck's Pyrogallic Acid

produces the highest intensity to be desired in a photographic plate, and, at the same time, the finest detail in light and shade required for the most perfect printing negative.

Under ordinary precaution, it retains all its superior qualities undiminished for an indefinite length of time.

WHEN ORDERING SPECIFY "MERCK'S."

TO BE HAD OF ALL DEALERS.