« PreviousContinue »
as large as the common lead-pans; and, a quantity of water being added, just sufficient to hold the alum in solation, the crystals are dissolved by boiling, and the saturated liquid is poured into casks where the alum crystallizes. After standing about 16 days, the casks are taken down, the residuary liquor, called tun water, is preserved, to be used as fresh liquor; and the alum remains in the form of a hollow cask. The outside is scraped clean, the scrapings, like the water, being kept to undergo a second purification ; after which, the alum is broken into masses, ready for the market.—The purification, or second crystallization, of the alum, is called roaching; a term that seems to be derived from Rocca, the name of a place in Syria, the site of the most ancient alum-work in the world.
It is only within these few years, that the process now described has become general. Previous to the year 1789, the alkaline lee was universally prepared from kelp; but at that time black ashes, made from the refuse of soap-boilers’ lees, were introduced along with kelp, and in 1794 the kelp began to be entirely laid aside. In 1801, muriate of potash was first used with the black ashes, and in two or three years began to supersede them. Until 1794, urine was considered as a necessary ingredient, and was put in along with the alkaline lee, to reduce the specific gravity of the hot liquor to the proper pitch. Since that time it has gradually fallen into disuse. In introducing these improvements, which are found to be highly advantageous, Lord Dnadas, the proprietor of Lofthouse alum-works, has had an important share.
New experiments in the art are generally tried with caution ; for, instances have occurred, in which rash attempts at improvement have occasioned the most serions loss. In 1753, an attempt was made at Loftus works to make sea-water supply the place of kelp; but it cost the adven, turers above £2000. At the same works, a severe loss was sustained in 1746 and 1747, by using Castleton coals for boiling the pans. In 1764, the experiment of burning the alum-mine in kilns was adopted at Pleasington, in Lancashire; and the undertaking caused a loss of above £1000. For some years before 1770, there was no alum-house at Saltwick works; the liquor was conveyed to Shields in vessels constructed for thạt purpose, to be boiled in an alum-house there, with a view to save expense in the price of coals, kelp, &c. but the scheme was not found to answer.
The method employed by the alum-makers to find the specific gravity of the liquor, or the lees, has long been named the alum-maker's secret ; but it is now pretty generally known. A bottle is procured, containing about one-third of a pint, and having a short neck, even at the top. The bottle is filled with distilled water, or clear spring water; and, a pair of sensible scales being got, the bottle is put into one scale, and a piece of lead is made exactly to balance it: this is called the counter-weight or water-weight. The bottle is then emptied and dried, and the counter-weight being put into one scale, and the empty bottle into the other, small lead shot is poured in beside the latter, till the scales are poised. The small shot, the weight of which exactly corresponds with that of the water which was in the bottle, is called 80 penny-weights ; and it is divided and subdivided so as to form 10, 20, 10, 5, and 23 pendy-weights ; with smaller
fractions, as low as į and \. With these weights, the relative specifie gavity of any fluid may be ascertained, 80 penny-weights being equivalent to 1.0, and i penny-weight to 1.0125. The counter-weight is always put in the saine scale with the other weights, in weighing any liquor in the bottle.
The quantity of calcined mine required to produce a ton of alum varies according to the quality of the rock, as well as the management of the process : the mine taken from the upper part of the rock being vastly richer than what is taken from the lower part. According to an experiment made with great care by Mr. Bathgate, 50 tons of good burnt mive will yield one ton of roached allum, with skilful management: but, in a general way, it requires from 120 to 130 tons of calcined mine to produce one top of alum. Each pan is reckoned to produce on an average 4 cwt. of alum daily, and to require about 18 bushels of coals, Winchester measure. About 22 tons of muriate of potash are necessary to produce 100 tons of alum.
The analysis of alum has been variously stated. According to Vanquelin, it is composed of 30:52 parts, sulphuric acid ; 10-50, alumine; 10:40, potash; and 48-58, water. Mr. Winter's analysis gives the following result; --Sulphuric acid, 33-34 ; alumine, 11:38 ; potash, 9:16; and water, 46:12. If urine be employed in the process, the alum contains also a portion of ammonia.
Miscellaneous Correspondence, &c.
QUERY ON THE ROT IN SHEEP.
To the Editors of the Northern Star. J SHALL be glad, as a subscriber to your Numbers, to find any attention in them directed to the interests of agriculture, couvinced as I am that the welfare of the country is so intimately involved in the judicious cultiva. tion of that science: I beg of you, therefore, to insert the following question, in hopes that it may elicit from intelligent farmers in the neighbours bood, such information as may be calculated to diminish an evil in its na ture so truly alarming.
It is, I believe, a fact, that at this time not less than two-thirds of the sheep are affected with the rot; and the object of my paper is simply to ask, If the experience of any neighbouring farmer has yet led him to any mode of treatment which promises to be more efficient than that imperfect one which has hitherto obtained ? Surely the great importance of this subject should rescue it from neglect; and yet I have to learn that that duë attention which it merits has been paid to it. I shall be gratified to see in your future Numbers any observations which may throw light upon it.
Sheffield, March, 1818.
THE ACORN:-AN APOLOGUE.
Which babes might play with :
Time was wben, settling on thy leaf, a fly
COWPER's Yardley Oak. A HIGH wind shook the last acorn from an old Oak. In the following night, the tree itself was thrown down by the tempest. It had lived through five centuries, but though in that period it had produced millions of acorns, they had all been devoured by swine, or perished where they fell. Yet there was a prophecy, nearly coeval with the deluge, in the family, that from the fruit of this Oak there should spriog a mighty forest. Age after age the venerable tree, decliging in strength, and decaying from the core, till the shell of the trapk, and a stanted brauch bearing six leaves and a single acora, were all the insignia of its ancient honours ; age after age, the ve perable tree looked anxiously for tokens of the fulfilment of this prediction, in the growth of some sapling from one of its acoras. deferred maketh the heart sick ; but when the desire cometh, it is a tree of life.” The old Oak knew this ; and to the last moment of its existence believing, that He who had promised could not fail to perform, it prayed even as it lay prostrate on the ground, that its orphan offspring, the sole sarvivor of its stock, might in due time be quickened, shoot up, and become the parent of a great family. While it was praying, the ceased to circulate through its rigid veins, and the old Oak died, lamented by all the trees of the field. A hoary-headed man, who appeared as far stricken in years as the tree itself, though but an infant in comparison with it, removed the relics, and built an hermitage of them in a solitary corner of his grounds, whither he was wont to retire for devotion, and where he was at length found dead, in the attitude of prayer, with the expression of hope full of immortality on his countenance.
The solitary Acorn had fallen into the deserted pest of a field-mouse, and the gigantic trunk of its progenitor descending close by, crushed the turf over its head, and buried it alive. In darkness, alone, and immoreably wedged, the poor Acorn gave itself over for lost: and yet it could not but remember how merrily it had lived on the little bough that nourished it, dancing in the breeze, drinking the dew, enjoying the light; it could not bat remember the radiance of the sun, the beauty of the moon, the multitude of the stars, the verdure of the earth, the diversity of hill and dale, the river rolling at the root of its aged sire ; it could not but remember the sounds of winds, and birds, and waters, the motions and colours of the clouds, the forms, voices, and actions of men and animals, which it had remarked during its ponage above; it could not but remember these, and remember them with regret, -regret, acuminated to despair, in the apprehen: sion that soon it must cease to hear, and see, and feel for ever. VOL. II.
While the Acorn lay thus raminating on its helplessness, insignificance, and misery, it heard, or thought it heard, a voice from heaven saying to it, Produce an Oak!”. 66 Produce an Oak !" repeated the Acorn to itself ; " that's impossible ; no, it is not impossible ; with God nothing is impossible; and if He coinmands me, I can do it, and I will do it." The Acorn had well learnt this lesson of faith from its parent, that the Ruler of the Universe always gives power to his creatures to do what he requires of them.
Immediately through every perve of its frame, it felt a spirit in motion ; and the germ between its double kernel, though small enough to pass through the
eye of a needle, received a consciousness, that a whole treeroots, bark, bole, branches, leaves and fature fruit-lay folded, with exquisite minuteness, in the fairy casket of its bulb. There was no self-delu. sion in the Acorn; it had humbled itself, and it was about to be exalted. From that crisis, though the shell and the kernels began to waste away, the germ fed upon them; presently it swelled and put forth fibres which insinuated themselves through the soil to secure a permanent foot-hold. In spring there appeared above-ground a tiny shoot, which opened and presented
-66 two lobes protruding, pair'd exact." The new-sprung plant was lower than the blades of grass, that rose in myriads around, and looked down contemptuously upon it as a stranger, whose shape was uncouth, and whose language they did not understand.
Hours days, weeks, months, passed swiftly away, and so did the grasses, but the offspring of the Acorn survived them all, and continued to grow till it became a sprig, with two full-formed leaves, and a bud between them, which tempted the bee and the butterfly to alight on their way, while the grasshopper chirped at its foot, or skipped over its head; nay, so vigorously did it push forth on the right and on the left, as well as upward, that the cowslip was compelled to hang its blossoms awry to make room for the syivan intruder. Now year followed year, till the spring became a sapling, and one generation of men died after another, while the sapling expanded into an oak, and the oak advanced through two cepturies towards maturity. All this time the tree from the Acorn had preserved its innocence and its humility ; though rooted in the earth, it aspired towards heaven; the nourishment which it drew from the soil and the river and the atmosphere, it received as the bounty of Providence, and it was thankful.
Meanwhile, the occasional lightnings played harmlessly around its head, and the tempest that agitated it above, caused its roots to strike deeper below. Thus flourished the Oak, the pride and the admiration of the whole country. The birds roosted. and sang amongst its branches. The cattle chewed the cud, and reposed under its shelter. The lambkins in April ran races round the mount which its roots had upheaved from the plain. Man approached it with veneration, and as he lifted up his eye at 80 magnificent a spectacle, he glanced beyond it to the sky, and thought,
“ How much glory can the Creator confer on one of his inferior works! How much of himself may be seen even in a tree !"
But one thing was wanting to consummate its felicity ;-the Oak wag barren; pot án acorn had ever glistened in a rough cup on the most luxuriant of its boughs, though their foliage spread thick and beautiful to the sun, and rustled musically in the breeze; and though autumn in its turn brought a second spring of leaves, so delicately tinged, that they seemed to be the blossoms of the first. Now it came to pass, during a hard winter, that an old raven, driven by stress of weather from the sea-coast and travelling far inland, alighted one clear cold morning on the topmost twig of the Oak. Though stripped of its summer-attire, the grace and majesty of its form were the more striking in the fair proportions of its tail stem and naked branches, here and there tufted with brown clusters of dry leaves, of which now one, then another, fell,
or slowly circling through the waving air," to the ground, where thousands of their brethren lay strown at the feet of their parent, in all stages of decay; some brilliantly bespangled with pearls of ice, and many so cariously pencilled with hoar-frost, that every vein was distinguishable. The raven, who was thin of plumage, and irongray with years, looked as if he had seen better days, but would never see such again. Age and adversity had soured his disposition, if ever it had been good, so that he could no longer behold happiness without envy, nor contemplate innocence without hankering to betray it; for happiness he knew was inseparable from innocence, and rarely, if ever, associated with guilt. While he sate shivering in the wind, that lifted up his ragged feathers with every breath, his lank sides were exposed to the chaffinches and réd-breasts that hopped on the lower boughs, peeping askance at the strauger, wondering whence he came, and thinking not a whit the less handsomely of themselves and their gay plumage in coinparison with him.
Now Ralph was a soothsayer, and many an evil omen had he exhibitedto the
poor fishermen on the coast where his haunt was; soaring delighted in anticipation of the storm, and preying when it was over on the carcases of shipwrecked mariners. As he understood all languages that were spoken in the days of fable, he quickly entered into conversation with the Oak, wormed out its whole history, and was sagacious enough to discover,what the tree itself scarcely suspected, that innocent and happy as it was, secret anxiety had began to corrode its heart, lest, notwithstanding its health, strength, and virtue, aud notwithstanding the ancient prophecy, it might at length die without issue, there being little hope, after such an age of sterility, that it would yet become fruitful.
The subtle raven caught his cue, and by a train of sophistry, of which history has not furnished the particulars, (perhaps lest others who are not trees should be beguiled by them,) he succeeded in persuading the Oak, that it was such a favourite of Providence, that the course of nature was suspended with respect to its destination, and it was either governed by such a mysterious heavenly influence, or had within itself such an origiDal power, that it could do or be whatever it pleased: thus, instead of propagating its species by acorns, it might continue to increase in bulk, in