From The Connecticut River Valley in Southern Vermont and New Hampshire: Historical Sketches by Lyman S. Hayes, Tuttle Co., Marble City Press, Rutland, VT., 1929, page 317:
POTASH MANUFACTURE WAS AN EARLY LEADDING INDUSTRY IN BELLO'VS FALLS
During the years when the Connecticut river furnnished the main artery of transportation to the markets of Hartford and New York, among the varied products of this section of New England which furnished one of the principal loadings of the flat boats was potash and pearlash. Today's inhabitants of this locality know but little of this important article manufactured in large quantities in this vicinity, or of the methods used to produce it.
For a number of years during the early part of the last century, the manufacture of potash and pearlash was an important industry. Pearlash was used as a substitute for baking soda, it being of a similar nature. Potash works were located in different parts of this town, as well as all over New England. The location of one place where it was made is still pointed out between Saxtons River and Cambridgeport. One of the largest works in this vicinity was located across the Connecticut river from Bellows Falls, a few rods south of the old toll bridge, on the east side of the highway, on the first hill the traveler descends in going towards Walpole. From these extensive works the hill mentioned has, until very recent years, been known as "Potash Hill." This industry was the first manufacturing of any kind at North Walpole except the two saw mills on Governor's brook, which flows through the village.
Potash and pearlash were made wholly from wood ashes. When the first settlers came to this vicinity, it was necessary to dispose in some way of the immense [318] quantities of trees that then cumbered the ground. For this reason large patches of forest were felled, the logs were thrown up in piles, and when sufficiently dry were burned. The ashes were then placed in leaches and water was poured upon them. The water, trickling through the ashes formed lye, which was boiled in a large iron kettle.
In a majority of the settlements large public potash works soon came into existence, like those mentioned above, and to these many of the settlers carried their ashes instead of making their potash at home. These were rude wooden structures, some of them being called potash, and others pearlash works.
At the potash works might be seen the huge leaches and the cauldron kettles employed in the making of potash, while at the pearlash works were immense ovens in which potash was baked. When it was of the right consistency it was stirred, and thus broken into lumps; it was then of a pearly white color-hence the name, "pearl-ash." These products were used by the women of that day in making soap, and they formed a staple article of merchandise for shipment to the large cities. From this town they were shipped down the river by boat in large quantities.