The lye used for the purpose of cleaning a form is a solution of alkali in water; it ought to be made of the best pearl ash. The usual proportion is one pound of pearl ash to a gallon of soft water; it should be stirred up with a stick till the alkali dissolves, which soon takes place. It is generally kept in a large jar, with a cover to it, which some master printers lock; but more frequently the cover is loose for the pressmen to have free access to it; the cover should however be kept on, to prevent dust and dirt getting into the jar.
If hard water be used, it will require a greater quantity of pearl ash; as the acid in the water will combine with some of the alkali to neutralise it, which of course will have the effect of making the lye weaker than if soft water, with which there is no such combination, had been used.
An intelligent pressman once informed me, that in the country he had frequently made lye, by boiling together a peck of wood ashes and nearly a quarter of a peck of quicklime, in a pailful and a half of soft water, and afterwards straining the decoction for use.
This is, in fact, soap lye, which is made caustic by the quicklime: lye from the soap boilers has indeed of late years been used by many master printers in the metropolis; but it requires to be kept constantly covered in order to exclude the air, which, when the lye is exposed, combines with it and renders it mild, thus destroying its power. I have always found that this lye affects the hands and makes them sore, as if chapped, when washed in it to take off ink.
In the choice of pearl ash the following table, from Vauquelin, may be found useful, which shows all the substances contained in six kinds of potash.
|Real Potash||Sulphate of Potash||Muriate of Potash||Insoluble Residium||Carbonic Acid and Water|
|1152 of Russian Potash||772||65||5||56||254 = 1152|
|1152 of American Potash||857||154||20||2||119 = 1152|
|1152 of Perl Ash||754||80||4||6||308 = 1152|
|1152 of Treves Potash||720||165||44||24||199 = 1152|
|1152 of Dantzic Potash||603||152||14||79||304 = 1152|
|1152 of Vosges Potash||444||148||510||34||304 = 1152|
There is evidently an error in this statement as to the component parts of the last article, the Vosges potash, which appears to be with respect to the quantity of the muriate of potash; but the table shows that the American potash is by far the best, and the Dantzic potash the worst of the six analysed.
The following observations from Kirwan on Manures, may also be serviceable, particularly to printers who are so situated as to find it necessary to make their lye from the ashes of vegetables.
“ Alkaline salts are of great importance in several arts, the proportion of ashes afforded by different vegetables, and that of alkali by the ashes of each sort of vegetable, has been accurately attended to: the following are the best authenticated results of the experiments made with this view.
” One thousand pounds of the following vegetables, perfectly dry, and burned in a clean chimney and open fire, afforded the quantity of ashes, and saline matter, exhibited in the annexed tables.
|One thousand Pounds||Pounds of Ashes||Pounds of Salt|
|Stalks of Turkey Wheat or Maize||86.6||17.5|
|Ditto of Sunflower||57.||20.|
|Fern cut in August||34.46||4.25 Home.|
|Stalks of Turkey Wheat or Maize||198 lbs|
|Ditto of Sunflower||349|
|Fern cut in August||116, or 125 according to Wildenheim|
Thus though fumitory gives the greatest weight of saline product from a given weight of the dry vegetable, yet from a given weight of ashes wormwood produces above double the weight of saline matter.
In Yorkshire the women use the ashes of the ash tree to make a lye to scour their pewter dishes and plates, in preference to the ashes of any other wood; as this is the result of experience, I should be led to suppose that they contain a great proportional quantity of pearl ash.