the ash is then taken.  To determine the percentage of wool, a sample of the paper is dried at 230 deg.  Fahrenheit and weighed, boiled in a porcelain dish in potash lye 12 deg.  B. strong, and frequently stirred with a glass rod.  The wool fiber soon dissolves in the potash lye, while the vegetable fiber remains unaltered.  The pulpy mass resulting is placed upon a filter, dried at 212 deg.  Fahrenheit, and after the potash lye has dripped off, the residue, consisting of vegetable fiber and earthy ash ingredients, is washed until the water ceases to dissolve anything.  The residue dried at 212 deg.  Fahrenheit is weighed with a filter, after which that of the latter is deducted.  The loss of weight experienced is essentially equal to the loss of the wool fiber.  If the filtrate is saturated with hydrochloric acid, the dissolved wool fiber separates again, and after having been collected upon a weighed filter, it may be weighed and the quantity ascertained.

The weight of the mineral substances in the raw paper is ascertained by analyzing the ash in a manner similar to that above described.  The several constituents of the ash and the mineral added to the raw paper are ascertained as follows:  Sufficient of the paper is calcined in the manner described; a known quantity of the ash is weighed and thrown into a small porcelain dish containing a little distilled water and an excess of chemically pure hydrochloric acid.  In this solution are dissolved the carbonates, carbonate of lime, carbonate of magnesia, a little of sulphate of alumina, as well as metallic oxides, while silicate of magnesia, silicic acid, sulphate of lime (gypsum) remain undissolved.  The substance is heated until the water and excess of free hydrochloric acid have been driven off; it is then moistened with a little hydrochloric acid, diluted with distilled water and heated.  The undissolved residue is by filtering separated from the dissolved, the filter washed with distilled water, and the wash water added to the filtrate.  The undissolved residue is dried, and after the filter has also been burned in due manner and the ash added, the weight is ascertained.  It consists of clay, sand, silicic acid and gypsum.

The filtrate is then poured into a cylinder capable of holding 100 cubic centimeters, and furnished with a scale; sufficient distilled water is then added until the well-shaken fluid measures precisely 100 cubic centimeters.  By means of this measuring instrument, the filtrate is then divided into two equal portions.  One of these parts is in a beaker glass over-saturated with chemically pure chloride of ammonia, whereby any iron of oxide present and a little dissolved alumina fall down as deposit.  The precipitate is separated by filtering, washed, dried at 212 deg.  Fahrenheit and weighed.  To the filtrate is then added a solution of oxalate of ammonia until a white precipitate of oxalate of lime is formed.  This precipitate is separated by filtering, washed, dried and when separated from