mostly located in the Hebrides. The end of war reintroduced competition from Spanish barilla, a cheaper and richer product. This, combined with the reduction of duty on the foreign import, and the discovery that cheaper alkali could be extracted from common salt, destroyed the seasonal employment of an estimated 25 to 40 thousand crofters. There was little prospect of alternative employment; the only possibility was fishing, which was also in decline at the same time. The overall population of the Western Isles had grown by 80 per cent between 1755 and 1821. The economic collapse of an industry that was a major employer in a greatly over-populated region had an inevitable result. Not only did the level of poverty increase in the general population, but many landlords, failing to make prompt adjustments to their catastrophic fall in income, descended into debt and bankruptcy. Famine The Highlands, as an agriculturally marginal area, was the last part of mainland Britain to remain at risk of famine, with notable instances before the 19th century in 1680, 1688, the 1690s, 1740–1, 1756 and 1782–3. The history of the trade in meal suggests that the region balanced this import with exporting cattle, leading to a substantial reliance on trade for survival that was greater than anywhere else in Britain. There was near-contemporaneous dispute as to the severity of famines in the pre-clearance Highlands: in 1845, the Sutherland estate management argued over the level of famine relief that had been needed in the past, including this opinion: "The cattle on Sutherland were that Spring dying from scarcity of provender... and this is the condition to which your morbid Philanthropists of the present day refer as the days of comfort for the wretched Highlanders." (11 June 1845 letter to James Loch). Even accepting the level of debate on the subject among historians and the incomplete body of evidence, there is a clear case that, for example, pre-clearance Strathnaver (in Sutherland) experienced recurrent famine in a society operating at the margin of subsistence. Crofting communities became more common in the early part of the 19th century. Particularly in the West Highlands and the Isles, the residents of these small agricultural plots were reliant on potatoes for at least three quarters of their diet. Until 1750, potatoes had been relatively uncommon in the Highlands. With a crop yield four times higher than oats, they became an integral part of