The preparation of carrageen size is confined to one ever recurring manipulation, which must be repeated every eight days, if an always good and useful size is desired; the expenses are very trifling, a few cents for the best kind of carrageen. If bought in larger quantities the expenses for carrageen can still be reduced. For the preparation of the size take a new pot, which must always be used for this purpose exclusively, pour in six quarts of water, which quantity is sufficient to twice or three times fill the usual marbling trough, add 2-1/2 ounces of Carrageen moss and boil until the water bubbles up several times. A longer boiling is injurious because the mucilage becomes flaky and muddy. 2/5 of an ounce of Carrageen to one quart of water is fully sufficient to produce a consistent size, provided that only the best Carrageen is used. Soft water or rain water was formerly used exclusively for preparing the size, as by using it a greater durability was obtained. 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.