Born with the ear attuned to music and the eye to observe beauty, the hand of Art was to trace and make permanent the fleeting forms which melody and the eye impressed upon the soul of man. In fact modern science has demonstrated that tones and colours are inseparable. Bell and Tainter with their _photophone_ have converted the undulatory waves of light into the sweetest music. Reversing the process, beautiful flashes of light have been produced from musical vibrations by the _phonophote_ of M. Coulon and the _phonoscope_ of Henry Edmunds. Entrancing as the story is, we can only here allude to a few of those discoveries and inventions that have become the handmaidens of the art which guided the chisel of Phidias and inspired the brush of Raphael. _Photography._--The art of producing permanent images of the “human face divine,” natural scenes, and other objects, by the agency of light, is due more to the discoveries of the chemist than to the inventions of the mechanic; and to the chemists of this century. At the same time a mechanical invention of old times became a necessary appliance in the reduction of the theories of the chemists to practice:--The _Camera Obscura_, that dark box in which a mirror is placed, provided also with a piece of ground glass or white cardboard paper, and having a projecting part at one end in which a lens is placed, whereby when the lens part is directed to an object an image of the same is thrown by the rays of light focused by the lens upon the mirror, and reflected by the mirror to the glass or paper board, was invented by Roger Bacon about 1297, or by Alberta in 1437, described by Leonardo da Vinci in 1500 as an imitation of the structure of the eye, again by Baptista Porta in 1589, and remodelled by Sir Isaac Newton in 1700. Until the 19th century it was used only in the taking of sketches and scenes on or from the card or glass on which the reflection was thrown. Celebrated chemists such as Sheele of the 18th century, and Ritter, Wollaston, Sir Humphry Davy, Young, Gay-Lussac, Thenard, and others in the early part of the 19th century, began to turn their attention to the chemical and molecular changes which the sunlight and its separate rays effected in certain substances, and especially upon certain compounds of silver. In sensitising the receiving paper, glass, or metal with such a compound it must necessarily be protected from exposure to sunlight, and this fact, together with the desire to sensitise the image produced by the camera, not only suggested but seemed to render that instrument indispensable to photography. Nevertheless the experiments of chemists fell short of the high mark, and it was reserved for an artist to unite the efforts of the sun and the chemists in a successful instrument.