From reading and speculation he soon passed to experiment. But at this time he had never seen a chemical operation performed, and had little or no acquaintance with even as much as the forms of chemical apparatus. Phials, wine-glasses, tea-cups, and tobacco-pipes, with an occasional earthen crucible, were all the paraphernalia he could command; the common mineral acids, the alkalis, and a few drugs from the surgery constituted his stock of chemicals. Of the nature of these early trials we know little. It is, however, almost certain that the experiments with sea-weed, described in his two essays “On Heat, Light and the Combinations of Light” and “On the Generation of Phosoxygen and the Causes of the Colours of Organic Beings” (see p. 30), were made at this time, and it is highly probable that the experiments on land-plants, which are directly related to those on the _Fuci_ and are described in connection with them, were made at the same period. That he pursued his experiments with characteristic ardour is borne out by the testimony of members of his family, particularly by that of his sister, who sometimes acted as his assistant, and whose dress too frequently suffered from the corrosive action of his chemicals. The good Mr. Tonkin and his worthy brother, the Reverend Doctor, were also from time to time abruptly and unexpectedly made aware of his zeal. “This boy Humphry is incorrigible! He will blow us all into the air!” were occasional exclamations heard to follow the alarming noises which now and then proceeded from the laboratory. The well-known anecdote of the syringe which had formed part of a case of instruments of a shipwrecked French surgeon, and which Davy had ingeniously converted into an air-pump, although related by Dr. Paris “with a minuteness and vivacity worthy of Defoe,” is, in all probability, apocryphal. Nor has Lord Brougham’s story, that his devotion to chemical experiments and “his dislike to the shop” resulted in a disagreement with his master, and that “he went to another in the same place,” where “he continued in the same course,” any surer foundation in fact. Two or three circumstances conduced to develop Davy’s taste for scientific pursuits, and to extend his opportunities for observation and experiment. One was his acquaintance with Mr. Gregory Watt; another was his introduction to Mr. Davies Gilbert (then Mr. Davies Giddy), a Cornish gentleman of wealth and position, who lived to succeed him in the presidential chair of the Royal Society.