by precipitations is considered soft. Carbonates of sodium or potassium are strong bases, exactly the opposite of acids, and they therefore prohibit the oxidation in plant mucilages. This chemical reaction against the formation of acids I used for the purpose of prohibiting a deterioration of the size by adding sodium, in which I was thoroughly successful, as it can easily be preserved in a cool place for even eight or ten days.

Two obstacles offered themselves, which I have overcome after a tireless and thorough investigation, first the strongly alkaline property of the size which was generated by the added carbonate of sodium and second the fermentation of lactic acid which occurred notwithstanding the sodium and made the size useless.

The presence of alkalies was injurious to such colors, chemically bound to bodies, among which red is most affected. The coloring matter was removed from the bodies and became mixed by running with the size, causing the size to become soiled. Even the shade of the color was changed to another which was nearer to purple, and in this way, the beauty of the color was greatly lessened. The second obstacle is the fermentation of lactic acids which always occurs where starch flour is in the solution, causing in consistent sizes a gradual thinning out and even a destruction of the size.

It was not my aim to save the size from destruction forever, as this is impossible (laws of nature cannot be obliterated at will) but to keep it useful for a certain period of time, and this I achieved after many experiments by using borax.

Borax is a neutral salt of strongly antiseptic properties, prohibiting fermentation and decomposition where neither base nor acid predominate. Borax is produced by neutralization of boracic acid with carbonate of sodium and can be bought at every drug-store.

This salt is sold in crystals of the size of walnuts; for our purpose it is ground to powder and is kept for use in a closed vessel. The size is first used without any addition of borax as it is then better adapted for producing comb and other drawn edges, and only after some time has elapsed, in summer 36, in winter 48 hours, are 150 grains of borax added to the size, whereupon the size, having been repeatedly stirred to dissolve the salt, will keep entirely good and useful for a period of eight days without doing any harm to the colors. On a size which contains borax, the colors expand in a much greater degree than upon unadulterated size, without impairing the consistency of the mucilage. An unadulterated size is therefore, better for marbled and veined edges, but if it be desired to produce only marbled and veined edges on the size, it is advisable to add borax to the water before boiling the carrageen moss.

As the influence of temperature is important in marbling, and the production of beautiful edges is often jeopardized by it, it should therefore have the most careful attention. Every glutinous mass acquires, according to the difference of the temperature of the size and air, in one-half to one-quarter of a minute, a film (top) which forms through natural evaporation.

On a size which has such a film, or top, the colors do not spread out in such circular forms as on a size on which the colors are quickly thrown right after the film (top) has been taken off, but form star-like veined spots which are torn by the film in all directions.

Even in the normal expansion of the drops of color, it often happens, that the rim of the drop is jagged, the cause being that the size already possessed a thin top, which was not yet sufficient to prevent the expanding of the colors. If the size be left standing for a half-hour or an hour before throwing on the color without having at first removed the top of the size, the drop will tear a hole into this film and will sink, even if quite a large quantity of gall had been added. This explains the contraction and the sinking down of colors on a still warm size, inasmuch as the top is formed by evaporation of the warm mucilage, so quickly and so thick, that the color which had already begun to spread out is pressed together by it and is forced to sink.

The greater the difference of temperature between the size and air, the quicker is the top formed. It is therefore a rule, that the size should be allowed to cool off in the same room, in which the marbling occurs, because in this way a symmetrical degree of heat or cold of the size and air will be gained. On such a size, the formation of the top is much slower and thinner, so that even after one to one and a half minutes after removal of the top of the size, the colors can be thrown on without the occurrence of the starry formation.

I will here mention a fact to show the importance of temperature. As this point has given me much trouble and has taken much time and labor, it was my aim to find that mysterious effect which I was unable to overcome despite my numerous chemical experiments, until my eyes became opened and I saw accidentally that this obstacle was the difference of temperature of size and air. From that time on I was able to prosecute my labors without the slightest difficulty.

To show the excellence of my marbling colors, I used a great number of samples, perhaps several thousand, and in order to produce them I worked on Sunday so that I could employ my whole time to the good purpose. It was winter; on every Saturday I ordered two pots of size to be boiled, and to cool them off I placed them in a room, in which there was no heat. On Sunday morning I filtered the size through a loose linen cloth; it was as clear as crystal, it possessed the necessary consistency, and I was much pleased with the results, which I had expected to achieve.

I commenced the preparation of the colors in a separate flat vessel, using but little size, so as to keep the rest from being soiled, but I was greatly astonished, when the colors in spite of the addition of gall, which of course was carefully done by drops, first spread out and then again were contracted, the starry formation of the colors took place, whenever I was not quick enough after the taking off of the top to throw on the colors.

I was dumbfounded and could give no explanation for it; the size was sufficiently cooled off, it had been standing the proper length of time, the mucilage was excellent but in spite of all that, these difficulties occurred.

Thinking that I might be more successful, if I should do the marbling in the trough where there is more surface offered to the color to spread out, I filled the trough with size of a sufficient height and then commenced the marbling, but immediately after the first trial I instantly recognized that even here my experiments would have the same result. Although I threw on the color with great alacrity, right after the top had been taken off, the first drop spread out normally 4 inches, the second but three, the third two, and the fifth and sixth only one inch. In this way I received instead of an equally wide band of thrown on color, one which tapered to a point. If I had not worked according to the system which I shall describe in the chapter of throwing on of colors, I would have received already with the fourth drop, a star-like formation.

Whatever I did to avoid this obstacle was worthless, it was and remained a mystery and I was unable on that day to produce anything beautiful or worthy of consideration. This happened several times until, by accident, and through careful study I found the cause which was nothing but the fact, that the size was much colder than the air in the room in which I worked. The evaporation on the surface of the size was so great, that the top was formed nearly as quick as on warm size and therefore a favorable result was impossible.