fertilization and he has shown how to make the gas works
contribute to the fertility of the soil. In the soda industry,
the chemist can successfully claim that he has founded it,
developed it and brought it to its present state of perfection
and utility, but not without the help of other technical men;
the fundamental ideas were and are chemical. In the leather
industry, the chemist has given us all of the modern methods of
mineral tanning, and without them the modern leather industry
is unthinkable. In the case of vegetable-tanned leather he has
also stepped in, standardized the quality of incoming material
and of outgoing product. In the flour industry the chemist has
learned and taught how to select the proper grain for specific
purposes, to standardize the product, and how to make flour
available for certain specific culinary and food purposes. In
the brewing industry, the chemist has standardized the methods
of determining the quality of incoming material and of outgoing
products, and has assisted in the development of a product of a
quality far beyond that obtaining prior to his entry into that
industry. In the preservation of foods, the chemist made the
fundamental discoveries; up to twenty years ago, however, he
took little or no part in the commercial operations, but now is
almost indispensable to commercial success. In the water supply
of cities, the chemist has put certainty in the place of
uncertainty; he has learned and has shown how, by chemical
methods of treatment and control, raw water of varying quality
can be made to yield potable water of substantially uniform
composition and quality. The celluloid industry and the
nitro-cellulose industry owe their very existence and much of
their development to the chemist. In the glass industry the
chemist has learned and taught how to prepare glasses suitable