By and by it became known in what way to bind the coloring matter of plants to bodies and to make them serviceable in the art of painting and the graphic arts. Since that time progress in this field has been so rapid that we gaze in astonishment upon the achievements of the color chemistry of to-day. The progress which developed industrial art and caused it to flourish, was enhanced by a new and highly important invention, the industry of tar colors. It is wonderful how man through the vigor of his intellect, tears from nature her hidden treasures which have lain in obscurity for thousands and thousands of years. Who would have thought, that the antediluvian vegetation with its splendor of thousands of colors should celebrate its resurrection in aniline colors which by their splendid qualities of richness and intensity over-shadowed everything before them? It is a pity that we are only able to use these colors in limited numbers in our trade. Up to this time they are used more for dyeing purposes, because they are without body and possess two apparently insurmountable proclivities, 1st, they do not mix so intimately with oxides of metal as the organic coloring stuffs of plants and they cannot for a long period withstand the influence of light. In the meantime it is to be hoped with confidence, that science will soon find the solution for these difficulties. Already the forerunners of body colors have been discovered, a few which could withstand light have followed, as geranium lake in which the coloring matter is only bound to oxide of lead by surface adhesion. Furthermore scarlet lake, which, although bound to oxide of lead, has been put in such a state that it does not run and lastly the artificial krapp-(madder) lake and indigo, which have been produced from coal-tar and nearly equal to the good color lakes of the animal and floral kingdoms. The main attention in the production of these colors is directed to the end of finding those which are free of poison and will not fade, to make them serviceable to the historic art of painting. For the aniline color there is therefore a wide field open to experiment. Whether our interests and demands in regard to colors will be fulfilled is a question of time. Even the newer productions of the animal and vegetable kingdom already differ in quality from those indispensable to the art of marbling. I recommend to my honored colleagues to read my book with attention, so that the intended gain shall not be missed and the beautiful art of marbling may attain a larger circle of friends. THE AUTHOR. THE SIZE. THE SIZE. The first process in marbling is the preparation of THE SIZE on which the colors are to be floated. By the name of size is meant a consistent glutinous mass, which is obtained by boiling or dissolving with water certain bodies derived from the vegetable kingdom.