Of Locke's less-known friends, Dr. David Thomas must have died between 1687, when there is a letter from him to Locke, and 1700, when Locke speaks of having outlived him. Sir James Tyrrell, another old college friend, usually spoken of in Locke's correspondence as Musidore, was in communication with him as late as April, 1704, the year of his death. He had, as already stated, been present at the "meeting of five or six friends" in Locke's chamber, which first suggested the composition of the _Essay_. Edward Clarke, of Chipley, near Taunton, was another friend of old standing. He was elected member for Taunton in King William's second parliament, and from that time forward resided much in London. This circumstance probably deepened the intimacy between the two friends; at all events, during the remainder of Locke's life they are constantly associated. Locke advised Clarke as to the education of his children, one of whom, Betty, a little girl now about ten years old, seems to have been regarded by him with peculiar affection; in his letters he constantly speaks of her as "Mrs. Locke" and his "wife." The playful banter with which Locke treated his child friends affords unmistakable evidence of the kindness and simplicity of his heart. William Molyneux, who for many years represented the University of Dublin in the Irish parliament, referred to in the second edition of the _Essay_ as "that very ingenious and studious promoter of real knowledge, the worthy and learned Mr. Molyneux," "this thinking gentleman whom, though I have never had the happiness to see, I am proud to call my friend," first became acquainted with Locke in 1692. In his _Dioptrica Nova_, published in that year, he had paid Locke a graceful, if not an exaggerated, compliment. "To none do we owe, for a greater advancement in this part of philosophy," he said, speaking of logic, "than to the incomparable Mr. Locke, who hath rectified more received mistakes, and delivered more profound truths, established on experience and observation, for the direction of man's mind in the prosecution of knowledge, which I think may be properly termed logic, than are to be met with in all the volumes of the ancients. He has clearly overthrown all those metaphysical whimsies which infected men's brains with a spice of madness, whereby they feigned a knowledge where they had none, by making a noise with sounds without clear and distinct significations." Locke was pleased with the compliment, and a letter acknowledging the receipt of Molyneux's book was the beginning of a long correspondence between them, which ended only with the early death of Molyneux, at the age of forty-two, in 1698. For nearly six years the friends, though in constant correspondence, had never seen each other, Molyneux residing in Dublin, and suffering, like Locke, from feeble health, which prevented him from crossing the Channel. But the feeling of affection seems soon to have become as intense, notwithstanding