Through these experiments I unexpectedly gained a certain knowledge which enabled me to overcome the technical difficulties of the marbling art. The greater the difficulties the more they aroused my zeal to surmount them and the greater my joy when victory was won. During my investigations I saw, that not the color itself, but its body, to which the color is bound either in a natural or chemical way, forms the important part of the colors necessary to our purpose. No branch puts so many critical demands upon the preparation of colors as the art of marbling, because, aside from the most careful grating which can only be done by using the best of painter's colors, there must be a great power of divisibility and excellent covering qualities so that the pigments do not turn pale by the propelling power of the ox-gall expanding on the size, but retain in a dry state, their full lustre. It is therefore impossible without a more thorough knowledge of the chemistry of colors to find from the legion of colors, which are thrown upon the market, the ones best adapted to our art. So much more so as, in most recent times, by simplification in the manufacture of most colors their quality, for marbling, has most essentially deteriorated. Colors which are used for painting, lithography and printing with the greatest success may be entirely unfit for marbling. The cause is not to be found in their preparation for our purposes, but in the manufacture itself, as the qualities, which are indispensable are not known. The main attention in the manufacture is directed to the finding of colors free from poison and which will not fade, when exposed to light, if they are intended for a wholesale consumption in painting and the graphical art. All colors which we intend to use for marbling purposes must have body, because bodiless colors become mixed with the size and run off from the paper in marbling, they therefore can be designated as useless for our purpose. The most important composite parts of colors for marbling are certain substances, among which hydrates of argillaceous earths, tin and lead oxides and sulphate of barium are named as the best. A great number of coloring matters of organic origin, which are soluble in water, have the propensity in mixing with a solution of salts of lead, tin, and argillaceous earths, with a metallic oxide to form a compound which is soluble with difficulty (and is termed insoluble,) when the latter is precipitated from the solution by an alkali. The precipitations which are obtained in this way are known as lake dyes. Of greater importance for the quality of the marbling colors are the physical conditions of these precipitates, they are either crystallized or amorphous, the former not possessing any value to us. The serviceable, i. e. the amorphous precipitates, by their quality of great divisibility give excellent colors.