While the process was patented in 1841, on 23 September, 1840, Talbot discovered how a solution of gallic acid could be used to bring out an image made on chemically treated paper, even if it had just been exposed for a few seconds. He derived the name from the Greek word ‘kalos’, which means ‘beautiful.’ This process further increased the possibilities of subjects that could be used for photography. He made an unsuccessful attempt to negotiate a licensing agreement in Paris (1843). In 1844, he published a photographically illustrated book called The Pencil of Nature.