He inquired particularly after Rulman Merswin. This rich merchant had withdrawn from the world (with the consent of his wife) and devoted himself altogether to the contemplative life, a short time previous to the coming of the Black Death. His austerities had been almost fatal. Tauler’s last counsel to him was to lessen their severity. I saw him before I left, and he desired me to tell Tauler that the Layman had visited him more than once, and was now his spiritual guide. I informed the Doctor, moreover, that during the last year Merswin had been privately busied in writing a book, to be called _The Nine Rocks_, of which he did me the honour of reading to me a part.[135] The Doctor asking what I thought, I said it seemed to be the work of a powerful and sombre imagination, excited by the sufferings he had inflicted on himself, yet containing many solemn and most just rebukes of the vices prevalent. Tauler said that such excessive mortification in all classes, and especially among the clergy, often weakened, instead of exalting the intellect. He feared that the good Rulman would always lean too much on visions, voices, ecstasies, and the like, and never rise to the higher calm of unsensuous, imageless contemplation. The second time I visited Tauler, I found him reading—he told me for the fourth time—a book called _The Spiritual Nuptials_, by John Ruysbroek.[136] The Doctor praised it highly, and as I questioned him about it, offered to lend it me to read. I had heard of Ruysbroek as a master in spiritual mysteries, often holding intercourse by letter with the Friends of God in Cologne, Alsace, and even in the Oberland. I took the book home to my inn, and shut myself up to read it. Many parts of it I copied out. Not a few things in it I found hard to be understood, and consulting with the Doctor about them, he told me he purposed setting out in a few days to visit the author. Should I like to accompany him? I said ‘Yes, with all my heart.’ So we left Cologne to travel to the convent of Grünthal, in the heart of the forest of Soigne, not far from Louvain, whither the holy man, now sixty years of age, had of late retired.[137] From Cologne we journeyed direct to Aix-la-Chapelle. There we saw the chair in which the emperors sit when they are crowned. Its sides are of ivory, and the bottom is made of a piece of wood from Noah’s Ark. Tasted the water in the famous hot springs there. It is saltish; the physicians say of singular virtue, whether taken inwardly or outwardly. Saw near the town a water which is lukewarm, by reason of one of the hot springs which passes under it. There are bred in it fine fish, they say, which must be put in cold water two months before they are eaten.