having admired his earlier works, I entered another room which contained his later paintings! Are these really by the same hand? I asked myself on first inspecting them; or have they suffered in any way? On examining them, however, more closely, a question presented itself to my mind which was to me a subject of interesting diagnosis. Was the great change, which made the painter of "Crossing the Brook" afterward produce such pictures as "Shade and Darkness," caused by an ocular or cerebral disturbance? Researches into the life of Turner could not afford an answer to this question. All that I could learn was, that during the last five years of his life his power of vision as well as his intellect had suffered. In no way, however, did this account for the changes which began to manifest themselves about fifteen years before that time. The question could therefore only be answered by a direct study of his pictures from a purely scientific, and not at all from an aesthetic or artistic point of view.
I chose for this purpose pictures belonging to the middle of the period which I consider pathological, i.e., not quite healthy, and analyzed them in all their details, with regard to color, drawing, and distribution of light and shade.
It was particularly important to ascertain if the anomaly of the whole picture could be deduced from a regularly-recurring fault in its details. This fault is a vertical streakiness, which is caused by every illuminated point having been changed into a vertical line. The elongation is, generally speaking, in exact proportion to the brightness of the light; that is to say, the more intense the light which diffuses itself from the illuminated point in Nature, the longer becomes the line which represents it on the picture. Thus, for instance, there proceeds from the sun in the centre of a picture a vertical yellow streak, dividing it into two entirely distinct halves, which are not connected by any horizontal line. In Turner's earlier pictures, the disk of the sun is clearly defined, the light equally radiating to all parts; and, even where through the reflection of water a vertical streak is produced, there appears, distinctly marked through the vertical streak of light, the line of the horizon, the demarcation of the land in the foreground, and the outline of the waves in an horizontal direction. In the pictures, however, of which I am now speaking, the tracing of any detail is perfectly effaced when it falls in the vertical streak of light. Even less illuminated objects, like houses or figures, form considerably elongated streaks of light. In this manner, therefore, houses that stand near the water, or people in a boat, blend so entirely with the reflection in the water, that the horizontal line of demarcation between house and water or boat and water entirely disappears, and all becomes a conglomeration of vertical lines. Every thing that is abnormal in the shape of objects, in the drawing, and even in the coloring of the pictures of this period, can be explained by this vertical diffusion of light.
How and at what time did this anomaly develop itself?
