At Fontainebleau, on the banks of the Rhone, at Mont Blanc, at Vaucluse, Sir Humphrey's artistic nature voiced itself in song. He had the poet's temperament, intense, quick, earnest, ardent, aspiring. He loved science, and paid her homage; he loved poetry, and made her his rest and solace and soul-companion. At Florence he studied the diamond, and found it merely crystallized carbon. At Rome he met Canova, who showed him great attention, and to whom he wrote this sonnet:-- "Thou wast a light of brightness in an age When Italy was in the night of art: She was thy country; but the world thy stage, On which thou actedst thy creative part. Blameless thy life--thy manners, playful, mild, Master in art, but Nature's simplest child. Phidias of Rome! like him thou stand'st sublime: And after artists shall essay to climb To that high temple where thou dwell'st alone, Amidst the trophies thou from time hast won. Generous to all, but most to rising merit; By nobler praise awakening the spirit; Yet all unconscious of the eternal fame, The light of glory circling round thy name!" At Milan he met Volta, nearly seventy years old. "His conversation was not brilliant," he said; "his views rather limited, but marking great ingenuity. His manners were perfectly simple." Around Naples he investigated the phenomena of volcanic eruptions. On his return to London they bought a house in Grosvenor Square. He now published several papers: "Experiments and Observations on the Colors used in Painting by the Ancients"; "Experiments on a Solid Compound of Iodine and Oxygen, and on its Chemical Agencies"; "Action of Acids on the Salts usually called the Hyper-oxymuriates, and on the Gases produced from them." All his life, besides his ambition to be great, he desired to aid his fellow-men, and in the year 1815 he made a discovery which placed him among the benefactors of the race. In 1812 a terrible explosion of gas had taken place in a mine, causing the death of nearly a hundred men. The mine was on fire, and the mouth had to be closed, thus bringing sure death to the poor creatures within. Such accidents were so frequent, that a committee of mine proprietors visited the great chemist, to see if science could suggest a remedy. He at once visited several mines, investigated fire-damp, and found it to be light carburetted hydrogen. After a long and careful series of experiments through several months, he invented the safety-lamp, "a cage of wire gauze, which actually made prisoner the flame of the fire-damp, and in its prison consumed it; and whilst it confined the dangerous explosive flame, it permitted air to pass and light to escape; and though, from the combustion of the fire-damp, the cage might become red hot, yet still it acted the part of a safety-lamp."