In 1805 Dr. Clarke published a “Dissertation on the Sarcophagus in the British Museum,” which, though necessarily neglected by the public, is said to have given considerable satisfaction to the learned, and procured for its author many valuable acquaintances. Another and a very different subject employed his mind throughout a great part of the following year. This was no less a thing than matrimony; which, as soon as the idea got footing in his brain, occupied his ardent imagination to the exclusion of every thing else. His suit, however, was successful. The lady of his choice became his wife; and to increase this piece of good fortune, two livings, for he had entered into orders, were presented him by his friends, the one shortly before, and the other immediately after his marriage. He now occupied himself with lectures on mineralogy, which were delivered at the university to crowded audiences, and were a source of considerable profit. This, as he expected, led to his appointment as professor of mineralogy; and “thus,” says Mr. Otter, “were his most sanguine wishes crowned with success; and thus were his spirit and perseverance rewarded with one of the rarest and highest honours which the university could bestow.” Dr. Clarke now began to think of turning the treasures he had picked up in his travels to account; he sold his MSS. to the Bodleian Library at Oxford for 1000_l._, and his Greek coins to Mr. Payne Knight for 100 guineas. The publication of his travels next followed, and produced him a clear sum of 6595_l._ In the year 1814 his old passion for travelling revived, and an expedition was projected into the Grecian Archipelago for the purpose of collecting antiquities, manuscripts, &c. But he was overruled by his friend, who probably believed that his constitution was now unequal to the fatigue which would be the inevitable attendant on such a mission. To this scheme he would appear to have been urged by the extravagant manner in which he had for some time lived; but a more practicable, or at least a more certain mode of recovering from the effects of this false step presented itself; which was no other than reducing his expenses, and living within his income. This he had the courage to undertake and execute; and from that day forward seems to have led the life of a sensible man. His passion now took a new turn, and he was wholly absorbed by chymistry. In September, 1816, he wrote as follows to a friend: “I sacrificed the whole month of August to chymistry. Oh how I did work! It was delightful play to me, and I stuck to it day and night. At last, having blown off both my eyebrows and eyelashes, and nearly blown out both my eyes, I ended with a bang that shook all the houses round my lecture-room. The Cambridge paper has told you the result of all this alchymy, for I have actually decomposed the earths, and obtained them in a metallic form.”