The great epidemic of relapsing fever, typhus, dysentery, anasarca and purpura, which arose in Ireland in the end of 1846 or spring of 1847 and lasted until the beginning of 1849, had for its direct antecedents the more or less complete loss of the potato-crop through blight in two successive autumns, 1845 and 1846, while the state of distress and sickness was prolonged by the potato disease in 1847 and 1848[498]. The potato-blight, which caused so much alarm in Ireland for the first time in September, 1845, had been seen in Germany several years before, in Belgium in 1842, in Canada in 1844, and in England about the 19th of August, 1845. Shortly after the last date, it attacked the Irish potato-fields, first in Wexford, and before the end of the year it was estimated that one-third to one-half of the yield, which was a fifth larger than usual from the greater breadth planted and the abundant crop, was lost by absolute rottenness or unfitness for food, the process of decay being of a kind to make great progress after the tubers were pitted. The loss to Ireland was estimated at about one pound sterling per head of the population. Sir Robert Peel was keenly alive to the magnitude of the calamity which threatened the Irish peasantry. His first step was to summon to his aid a botanist, Dr Lindley, and a chemist, Dr Playfair; the latter went down to Drayton Manor, and joined the prime minister in examining samples of the diseased potatoes. The question was whether some chemical process could not be found to arrest the decay of the tubers. Sir Robert Peel, in a much talked-of address at the opening of the Tamworth Reading-Room in the winter of 1840, had hailed the rising sun of science and useful knowledge. It was only in reference to morals and religion that Peel’s deliverance called forth criticism, more particularly the memorable series of letters to the _Times_ by John Henry Newman. But one of Newman’s gibes was in a manner prophetic of Peel’s attitude in approaching the material distress of Ireland: “Let us, in consistency, take chemists for our cooks, and mineralogists for our masons.” The two professors proceeded to Ireland, but could only confirm the fact, already known, that one-third, or one-half, of the potato-crop would be lost.