In winter, when the room is heated, the size should be poured into the trough one hour before using, in summer the thing regulates itself because it is then unnecessary to keep the size in a cool place, the addition of borax being a sufficient protection against spoiling. But in spite of it all, in winter-time when in drawing the colors the fig-like formation should occur, it is advisable to return the size to the pot and to warm it up slightly so that the seasoned particles are dissolved, until an equal temperature is reached, whereupon after the lapse of one hour the marbling can again be proceeded with. Should the size be too thick the trouble can be remedied by the addition of some warm water. The quantity of mucilage contained in carrageen moss varies greatly, and the consistency of the size often depends upon the quality of the moss. The quantity which I gave as essential to the preparation of the size means first class moss. Should the consistency of the size be insufficient after the first trial then from 1/2 to 1 ounce of moss should be added as it is clear that the carrageen moss is not of prime quality. Before I speak of another variety of size, I will repeat the main condition which should meet with the attention of every layman and which are as follows; the size must not boil too long, in order that it may not become flaky and muddy, it should remain for cooling in the same room in which the marbling is carried on, so that the temperature of of it and the air are the same; the colors should be prepared separately on a small quantity of size so that the whole size cannot become soiled and, lastly, the top of the size should be taken off before the colors are thrown on, so that no film can form before the colors cover the surface of the size. The quicker the manipulation of marbling is executed the prettier are the edges produced. As soon as the size is covered with color, the formation of the film is prevented. As the size is one of the most important parts in the process of marbling, I recommend these main points to the special consideration of the reader. GUM TRAGACANTH. GUM TRAGACANTH. Gum tragacanth, also called gum-dragon, is the product of various species of astragalus which is found in Greece and Turkey and is a natural exudation of shrubs and from exudations resulting from incisions made in the stem near the root. This shrub is from 28 to 35 inches high and two inches in diameter. It is collected in July and August after the exudations have ceased. It is a hard, tough substance more or less white according to its purity in very irregular flattened shapes and in tortuous vermicular filaments. It contains aside from a little gum and starch, a consistent plant-mucilage without smell or taste and it is used in technical ways, in printing of textile fabrics and finishing, in producing plastic masses, as a binding medium for the production of confections and in the book-bindery for marbling size.