We have no certain knowledge as to the commencement of the art of painting. The Egyptians assert that it was invented among themselves, six thousand years before it passed into Greece; a vain boast—evidently. As to the Greeks, some say that it was invented at Sicyon, others at Corinth; but they all agree that it originated in tracing lines round the human shadow. The first stage of the art was this, the second the employment of single colors; a process known as “monochrome-painting.” The invention............