Page:Willich, A. F. M. - The Domestic Encyclopædia (Vol. 4, 1802).djvu/115

Rh wool. He directs ("Annales de Chimie," vol. 21) the ley to be prepared in the usual manner, and made boiling hot; when shreds or rags of any kind of woollen cloth are to be gradually thrown in, and they will be speedily dissolved.—Fresh portions are then to be sparingly added; the mixture must be constantly agitated: when no more of the woolly substance can be dissolved, the soap will be ready; and, when cool, is fit for use.—This compound has been tried in washing, and found to answer the same purposes as common soap: we therefore conceive, it might be advantageously substituted for that expensive article, in numerous families; provided the rags could be obtained in sufficient quantities, and at a reasonable price.

As various frauds are practised by the manufacturers, and especially by the retailers of soap, by adding ingredients that increase its weight, but diminish its value, we deem it our duty, to give a few hints for detecting such impositions. The liquor, generally employed for such nefarious purpose, is a strong brine made of common salt and water, which may be added to soap formed of tallow (the ingredient principally used in the manufactories of Britain), without rendering it softer, or less consistent. In order to prove this adulteration, it will be sufficient to expose a piece of the suspected soap to the air, for several days, when the water will evaporate, and the quantity thus fraudulently added, may be accurately ascertained, by the diminished weight of the soap. Several other methods have been contrived for corrupting this article, but these being neither so lucrative as that before stated, nor generally known, we are not disposed to propagate such knowledge. Hence, we shall proceed to review the principal patents that have been granted to speculators in this article; and next explain the uses to which soap may be applied.

In November, 1790, Mr. obtained a patent, for a method of preparing oils for manufacturing hard soap, either with, or without, the aid of any tallow, or other grease, at a cheaper than the usual rate. His process, however, is too complex to be understood, excepting by manufacturers: the inquisitive reader will, therefore, consult the 2d vol. of the Repertory of Arts, &c. where a diffuse specification is inserted.

In July, 1800, a patent was granted to Mr., for a method of making soap, by means of the volatile, mineral, and vegetable alkalies, &c. His invention consists in extracting the volatile alkali from urine, either by distillation, or in its raw state; and rendering it caustic by means of unslacked lime, in the proportion of one pint to eight of raw urine. These are poured into a cask for 6 or 8 hours, when the clear liquor is drawn off, and incorporated with the common materials for making soap. The patentee likewise employs such alkaline ley, and also the raw urine, for the purpose of strengthening the ordinary soap, so as to impart to it greater clearness and solidity. He farther observes, that such urinous lixivium may be profitably applied to the cleansing of raw goods from the unctuous matter with which they are impregnated; by boiling the liquor, and causing the steam that arises from the volatile alkali in a state of vapour,