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PROCEDURE. Weigh out two portions of sodium chloride of about 0.25-0.3 gram each and proceed with the precipitation of the silver chloride as described under Method A above. Pour the liquid above the precipitates through the filters, wash twice by decantation and transfer the precipitates to the filters, finally washing them until free from silver solution as described.

Wash the precipitate twice by decantation with warm water; then transfer it to the filter with the aid of a stirring-rod with a rubber tip and a stream from the wash-bottle. Examine the first portions of the filtrate which pass through the filter with great care for asbestos fibers, which are most likely to be lost at this point. Refilter the liquid if any fibers are visible.

The blue chromous chloride solution thus obtained is poured into a saturated solution of sodium acetate in an atmosphere of carbonic acid. A red precipitate of chromous acetate is formed, which is washed by decantation in water containing carbonic acid. This salt is relatively stable, and can be preserved for an indefinite time in a moist condition in stoppered bottles filled with carbonic acid.

Filtration was an easy matter, more especially in the case of A. Examining the yeasts under the microscope, immediately after decantation, we found that both of them remained very pure. The yeast in A was in little clusters, the globules of which were collected together, and appeared by their well-defined borders to be ready for an easy revival in contact with air.

The precipitated emulsion is now taken into the dark room and washed until the wash water shows no trace of color; if there be a large quantity, this is best done on a fine muslin filter; if a small quantity, by decantation. Having been thoroughly washed, I dissolve the pellicle in water by immersing the beaker containing it in the water bath.

Replace the beaker containing the original filtrate by a clean beaker, wash the precipitated sulphate by decantation with hot water, and subsequently upon the filter until it is freed from chlorides, testing the washings as described in the determination of iron.

It is one of the most powerful Solvents known in Chemistry: It is neither acid nor alcaline, and therefore is perfectly free from that saline Acrimony with which all the common Volatile Spirits abound: It has a greater Affinity with Gold than Aqua Regia has, altho' it will not dissolve it in the Mass, or whilst in it's Metallic Form; but if you add AETHER to a solution of Gold in Aqua Regia, it presently takes all the Gold from it's former Solvent, keeping it perfectly dissolved and suspended, without the least Precipitation; and becomes of a yellow Colour: The AETHER, thus saturated with the Gold, does not mix with the Aqua Regia, but may readily be separated from it by simple Decantation, and thus a true and safe Aurum potabile is readily prepared for those who want such a Medicine.

Filter off the yellow precipitate on a 9 cm. filter, and wash by decantation with a solution of ammonium nitrate made acid with nitric acid. Allow the precipitate to remain in the beaker as far as possible. Add 10 cc. of molybdate solution to the nitrate, and leave it for a few hours. It should then be carefully examined for a !yellow! precipitate; a white precipitate may be neglected.

This decantation and pouring on continue so long till all the Calx of Saturn be dissolved, then take all the dissolved Saturn, set it in a Bath, evaporate the Vinegar by a small fire, the Saturn will become a powder or lump.

Much time may often be saved by washing precipitates by decantation, i.e., by pouring over them, while still in the original vessel, considerable volumes of wash-water and allowing them to settle. The supernatant, clear wash-water is then decanted through the filter, so far as practicable without disturbing the precipitate, and a new portion of wash-water is added.