Remarks. - Filtration. - Filters and Strainers. - Form of Filters. - Filtering Medium. - How to Make Paper Filters. - Funnels. - Filtering Paper and How to Purify It. - Adulterated Filtering Paper. - Filtering Paper Pulp. - To Filter Larger Quantities. - A Simple Method. - Filtering Vessels. - Liquids that are Submitted to Filtration. - Filtration of Aqueous Solutions on a Small Scale. - Filtering Aqueous Solutions on a Large Scale. - Filtering Oils. - Filtering Syrups. - Filtering Tinctures and Dilute Spirits. - Clarification and Filtration of Vegetable Juices. - Clarifying Vegetable Infusions and Decoctions. - Filtering Corrosive Liquids. - Gaining Pre-cipitates. - First Runnings from a Filter. - Application of Filtering or Clarifying Powders. - Preparation of Filtering or Clarifying Powders or Compounds. - Formulas for Clarifying Powders or Compounds. - Self-acting Filters. - Pressure Filters. - Upward Filtration and Filter. - A Quick Filter. - Practical Filtering Apparatus.

Remarks

We beg the reader's special attention to the subject of the filtration and clarification of extracts, essences, oils, syrups, tinctures, vegetable juices, infusions and decoctions. It is of vital importance that the operator should be familiar with all the information here imparted, and study closely the rules laid down and methods employed.

In compiling this chapter we have borrowed from the works of several eminent chemists, and arranged it for the practical purposes of the mineral-water manufacturer, adding our own practical experience and sugges-^tions. Filtration. - Filtration is the separation of liquids from substances mechanically suspended in them, by passing them through media having pores sufficiently fine to retain or keep back the solid matter.

Filtration is one of the most common and useful of the chemico-mechanical operations of the arts, and its successful performance in an economical and expeditious manner is, therefore, a matter of the highest importance in the laboratory, and, indeed, in almost every branch of human skill and industry, in which liquids are employed. Simple in principle, and apparently easily performed, it is, nevertheless, one of those operations which require no less of care than of tact and experience to conduct it with certainty and success. The losses sustained in the laboratory, by defective manipulation in this particular, often exceed those arising from ignorance and accidents in every other department conducted in it.

Filtration is generally resorted to for the purpose of freeing liquids from feculence, dirt, and other foreign matter, and for obtaining them in a clear or transparent state; but, in some cases, it has for its object the collection of the suspended substances, as precipitates, etc, and in others both these intentions are combined.