United States or Nigeria ? Vote for the TOP Country of the Week !
The more unwieldy portions of an engine may be case hardened by prussiate of potash a salt made from animal substances, composed of two atoms of carbon and one of nitrogen, and which operates on the same principle as the charcoal. The iron is heated in the fire to a dull red heat, and the salt is either sprinkled upon it or rubbed on in a lump, or the iron is rubbed in the salt in powder.
Ferrocyanide of Potassium K Cfy+3HO, or K C N Fe+3HO, is generally known by the name of yellow prussiate of potassa. It contains ferrocyanogen, a compound radical, consisting of 1 eq. of metallic iron and 3 eq. of the elements of cyanogen, and is designated by the symbol Cfy. Cyanide of potassium is generated in large quantities.
Dry the moistened paper somewhat, leaving it just moist enough to hold a uniform layer of fine yellow prussiate of potash. A plate of glass with a light pressure should be placed on this. In a few hours dry the paper thoroughly, and carefully brush off the yellow prussiate of potash. The writing should come out a Prussian blue.
Take 1 lb. logwood, 1 gallon soft water, simmer in an iron vessel for one hour, then dissolve in a little hot water 24 grains bychromate of potash, and 12 grains prussiate of potash, and stir into the liquid while over the fire, then take it off and strain it through fine cloth. This ink is a jet black flows freely from the pen and will stand the test of oexylic acid.
Prussiate of potash when brought into contact with the perchloride of iron immediately turns the latter blue, but it does not affect the protochloride. A bath is first prepared consisting of ten parts perchloride of iron, five parts oxalic or some other vegetable acid, and one hundred parts water.
Dissolve six grains of red prussiate of potash in one drm. of distilled water; in another drm. of distilled water dissolve twelve grains of ammonio-citrate of iron. Mix the two solutions in a cup or saucer, and at once brush over the surface of clean strong paper. Cover the surface thoroughly, but apply no more than the paper will take up at once; it should become limp and moist, but not wet.
A drop or two of the prussiate solution then gives a brown colour, even if but traces of copper are present. Magnesia. Suppose lime and magnesia are present. You may first evaporate to a small bulk, adding a drop of hydrochloric acid if the liquid becomes muddy. Then add ammonia and ammonium oxalate, when lime alone is precipitated as the oxalate of lime.
Zollekoffer says, that in intermittent fevers the Prussiate of iron is in its effects superior to Cinchona bark, and says it never disagrees with the stomach, or creates nausea even in the most irritable state, while bark is not unfrequently rejected; a patient will recover from the influence of intermitting and remitting fevers, in the generality of cases, in much less time than is usual in those cases in which bark is employed.
In the shade, in clear weather, 2 to 6 minutes, and in cloudy weather, 15 to 40 minutes may be necessary. The printing may also be done by electric light. The print is now immersed in a bath consisting of 15 to 18 parts of prussiate of potash per 100 parts of water.
If the solution of cyanide of potassium that is used is strong, the greater portion of the ferrocyanide of potassium crystalises in the solution, and may be collected and preserved for use again. If the solution of cyanide of potassium used to dissolve the precipitate is dilute, it will be necessary to condense the liquor by evaporation to obtain the yellow prussiate in crystals.
Word Of The Day