When fermentation had fairly commenced, and all other parts of the top were covered with the creamy froth, a circular space about eight inches in diameter, remained quite bare, directly above the discharge-cocks in both tuns. As the fermentation advanced, these were covered like the other parts.
The frothy top now rising, began to assume a variegated appearance. Directly above the discharge-cocks, that glassy-looking, bluish-white appearance, was perceptible, which always indicates unsoundness or galvanic action. This appearance gradually extended in a circular manner, about half round the tuns, in different directions, so as to form two opposite semi-circles. Soon after, the heads rose to such a height as to run over the top of the squares, without the possibility of preventing or controlling the action. The first thing done was to cut off the communication between one of the tuns and the main pipe. This had at once the desired effect. The fermentations in this tun were regular, and perfectly under control, and the ale produced proved very good. Notwithstanding this instructive fact, it was some time before the parties could be prevailed upon to cut off the other communications in the same way. They persisted for some time in brewing their common beer in the two tuns above mentioned, and the results were uniformly bad. Had the author’s suggestions
