During my researches, regarding the durability of the varieties of sizes, I found means by which the influence of hard water on the ground can be suspended, so that spring and pump water can now be used without any danger.
Every kind of hard water contains mineral salts, spring water especially containing lime in smaller or larger quantities. This can be seen, when the soap, which is used in such water, curdles, because of the ingredients of soap stearine palmitic or fatty acids of sodium or potassium, form a combination with the lime, to carbonate of lime, and the potash soap is converted into an insoluble lime soap. If we add to hard water a quantity of sodium or potassium, the carbonate of lime is precipitated as a white or yellowish powder, according to the quantity of iron contained in the water, and a soft water remains.
The sun produces on a great scale in nature, what the chemist achieves on a smaller scale by evaporation or precipitation and cooling of steam, a water free of all mineral salts, which we call distilled water. Rain water is the same, but the flowing water derived from a river already contains mineral salts in greater or smaller quantities, which are brought into it by different springs and substances. The water gained 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.