COLOUR REPRESENTATION. _Highest_.--Perfectly distinct, bright, and natural. _First Suboctile_.--White cloth, blue china, argand coffee-pot, buff stand with sienna drawing, toast--all clear. _First Octile_.--All details seen perfectly. _First Quartile_.--Colours distinct and natural till I begin to puzzle over them. _Middlemost_.--Fairly distinct, though not certain that they are accurately recalled. _Last Quartile_.--Natural, but very indistinct. _Last Octile_.--Faint; can only recall colours by a special effort for each. _Last Suboctile_.--Power is nil. _Lowest_.--Power is nil. It may seem surprising that one out of every sixteen persons who are accustomed to use accurate expressions should speak of their mental imagery as perfectly clear and bright; but it is so, and many details are added in various returns emphasising the assertion. One of the commonest of these is to the effect, "If I could draw, I am sure I could draw perfectly from my mental image." That some artists, such as Blake, have really done so is beyond dispute, but I have little doubt that there is an unconscious exaggeration in these returns. My reason for saying so is that I have also returns from artists, who say as follows: "My imagery is so clear, that if I had been unable to draw I should have unhesitatingly said that I could draw from it." A foremost painter of the present day has used that expression. He finds deficiencies and gaps when he tries to draw from his mental vision. There is perhaps some analogy between these images and those of "faces in the fire." One may often fancy an exceedingly well-marked face or other object in the burning coals, but probably everybody will find, as I have done, that it is impossible to draw it, for as soon as its outlines are seriously studied, the fancy flies away. Mr. Flinders Petrie, a contributor of interesting experiments on kindred subjects to _Nature_, informs me that he habitually works out sums by aid of an imaginary sliding rule, which he sets in the desired way and reads off mentally. He does not usually visualise the whole rule, but only that part of it with which he is at the moment concerned (see Plate II. Fig. 34, where, however, the artist has not put in the divisions very correctly). I think this is one of the most striking cases of accurate visualising power it is possible to imagine. I have a few returns from chess-players who play games blindfolded; but the powers of such men to visualise the separate boards with different sets of men on the different boards, some ivory, some wood, and so forth, are well known, and I need not repeat them. I will rather give the following extract from an article in the _Pall Mall Gazette_, 27th June 1882, on the recent chess tournament at Vienna:--