Before the end of their London stay they visited the British Museum, the natural history and ethnographical curiosities being duly noted by Marianne. In deference to an expressed wish, Wolfgang presented the Museum with his printed sonatas and with a manuscript composition (20 K.), consisting of a short madrigal in four parts, "God is our Refuge," the melody being possibly suggested.[20038] Notwithstanding this, the treatment of it is an extraordinary proof not only of the boy's skill, but of his readiness in apprehending and adhering to an unaccustomed form.[20039] On July 24, 1765, they left London, remained one day in Canterbury, and passed the rest of the month at the country seat of Sir Horace Mann. In obedience to the repeated and earnest solicitations of the Dutch Ambassador, speaking as the mouthpiece of the Princess Caroline, of Nassau-Weilburg, L. Mozart, contrary to his original plan, consented to visit the Hague. He probably lays stress on this pressing invitation to excuse his lengthened absence from Salzburg. His leave of absence had long ago expired, {FIRST JOURNEY.} (44) and he was repeatedly urged to hasten his return; but he was firmly resolved with God's help, to carry out what he had begun. They had proceeded as far on their journey as Lille, when Wolfgang was seized with an illness which necessitated a delay of four weeks, and from which he had not quite recovered when he was in Ghent playing on the great organ of the Church of St. Bernard. They reached the Hague in the beginning of September, and met with a very gracious reception from the Prince of Orange and his sister the Princess of Weilburg. But now, Marianne, in her turn fell dangerously ill; was delirious for a week together, and received the last sacrament. "No one," writes the father, "could have heard unmoved the interview between myself, my wife, and daughter, and how we convinced the latter of the vanity of the world and the blessedness of early death, while Wolfgang was amusing himself with his music in another room." They did not neglect to have masses for Marianne's recovery said in Salzburg. On the Sunday that she was at her worst, Leopold opened the Gospel at the words: "Lord, come down, ere my child die;" but a new treatment of the case by Herr Schwenckel, physician to the Princess of Weilburg, was so successful, that he was soon able to acknowledge the prophetic significance of the words: "Thy daughter sleeps; thy faith hath saved thee." Scarcely was the father relieved from this anxiety when he was subjected to a still greater trial. Wolfgang was seized with a violent attack of fever, which reduced him to extreme weakness for several weeks. But even illness did not cripple the boy's mental activity. He insisted on having a board laid across his bed, on which he could write; and even when his little fingers refused their accustomed service he could scarcely be persuaded to cease writing and playing.