Mr. Black, a practical writer upon Brewing, has found that by the
practice of imbedding the fermentation-vats in the earth, and
connecting them by means of metallic pipes, an electrical current
passes through the beer and causes it to turn sour. As a preventive,
he proposed to place the vats upon wooden blocks, or on any other
non-conductors, so that they may be insulated. It has likewise been
ascertained that several brewers who had brewed excellent ale on the
south side of the street, on removing to the north have failed to
produce good ale.