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man subscribing himself J. B. are rarely to be met with. This who thinks there are many soils in earth is of fo light a texture, and so England that would answer the easily dissolved in water, that it is same purposes.
with it, and again
restored to its dry state by very moY far the greatest part of the derate wind and sunshine, when it
falt-petre consumed in Eu- is very apt to rise in a fine black duft, rope comes from the East Indies : fall upon the cloaths of travellers, almost all that is brought from and penetrate even to the skin. the Polish and Russian Ukraines, The country-folks allow the toor the neighbouring provinces, is kens of nitre to be these ; that the obtained by an elixiviation from earth or mould be of a deep black, earth and ashes. Farth may be soft to the touch, without any fandisupposed to participate both of ness, and easily reducible to an exvegetable and animal substances ; ceeding fine powder ; if it be and it is a necessary circumstance dungy, it then must have a kind that it should remain a long time of fatness ; if it discovers the cool quiet, uncultivated, and desart. taste of nitre ; if it seems to have Such is the constitution of many been left a long while undisturbed ; parts of the soil of the Ukraine and a particular symptom of its and Podolia, as this country has richness, is a nitrous efflorescence, lain uncultivated ever since about in the form of a white down, which the third century, when its ancient overspreads it; from which they inhabitants, the Getæ, were driven also infer that some town, village, out by the Bulgarians, whose por- sheep-fold, or burying-place, had terity were more addicted to the formerly occupied the spot. Above breeding of cattle than to agricul- all others they are fond of searchture. To which may be added the ing for it in certain hillocks, which Turkish and Coffac wars in the they call, in their language, mogely; last century which almost depopu- they are of a conical figure, and lated the country; yet in these our undoubtedly artificial, and the modays, new colonies having, through numents of battles fought there.* its natural fertility, been induced One of these, on account of its to settle here, it is now fufficiently fuperior fize called szeroka mogila, well cultivated.
or the great hill, near Granow, This vastly extended plain seems probably a very ancient one, has in a manner covered with black or yielded nitre continually for near dusky, red earth to the depth of a hundred years past. It is near some inches, and sometimes à foot, three hundred paces in diameter, under which lies an earth more or and seems, from the shape of its less white, chalky, calcareous, or a remains, to have been at least rock indurated out of some of these, three hundred feet high. It is intermixed with sea-shells of vari- commonly reported that a cere ous kinds, and in fuch plenty, that tain queen, having by exprefs the in some places it seems to consist account of a neighbouring king wholly of them. Clay and fand being oppressed by the enemy, Like the burrows or barrows on Salisbury Plain and Marlborough Downs.
hastened with an army to his affift- the ley, which is conveyed into ance, and through misinformation, them by hand-scoops. flew her own husband; whether The nitrous earth is first of all any human bones lie buried there, beat to a coarse powder with iron future time must discover.
spades, and cleared of stones and For manufacturing their falt- other hard substances, laid lightly petre, they make choice of a in heaps, and then brought to the place not far from a spot rich furnace. If it be very rich in nienough in nitre to keep them tre (indicated either by its fatness, continually at work for at least a or its downy efflorescence) they whole fummer ; and besides, such mix with it some of a poorer fort, as can supply them sufficiently with in equal quantity, but very black water and wood at an easy ex- and old : this is, in the language pence. The utensils they employ, of the chemists, with an animal are called by one name maydan, earth they combine one that is and consist of the following articles: purely vegetable. Last of all, they
1. A large copper boiler, con- add ashes, to the amount of about taining about 60 amphors, of 6 a fifth part of the whole, more or gallons, or about 54 pounds of less, as best suits their purpose, water each.
and mix them together. The 2. One hundred wooden tubs or ashes they commonly make use fats, open on the top, with a hole of are of the ash, which they have bored near the bottom, which
may in great plenty. If they have a be stopped occasionally ; each of quantity of urine at hand, they these holds a carr of earth, or about throw it in, but never any quick 4 or 5 amphors.
lime. Thus they prepare a suitable 3. Two very large casks of stock of earth at the beginning of about 100 amphors each.
the summer, and continue to do so 4. Wide troughs or coolers to as long as is necessary, so as never the number of 32, holding an am- to be in want of a fresh supply. phor each, or somewhat more, in Some are so provident as to prewhich the crystallization is to be pare beforehand a' quantity suffiperformed.
cient to last them through the 5. A sufficient number of am- whole course of the ensuing sumphors for fetching water.
mer : but the usual practice is to A pit is dug in the ground, of bring the earth, as soon as predepth sufficient for erecling a fur- pared, to the furnace, which is nace or fire-place at the bottom, done in the following manner. and receiving the boiler set in Into one of the above mentionwith bricks over it, with its brim ed tubs (No. 2.) they put one carr on a level with the surface, over of the prepared nitrous earth, that which brim is conftructed a cir- is, about four amphors; then they cular covering or border of wood fill up the vessel with cold water, about eight inches high, and this though some warm it, and add a lined with lute' to keep the ley quantity of alhes, if none had from boiling over. The two great been mixed up with the earth, casks are placed at a small dif- stirring the whole well with a tance, being destined to receive wooden staff; then they suffer
it to ftand twenty-four hours, only time the crystallization being com. ftirring it by times. After this pleted, they drain off the mother fpace they suffer the ley to run out of nitre, and return it into the boilat the hole near the bottom, and The crystals are taken out and put it into the two large casks, dried, but as they never prove clean, (No 3.) They clear the tubs of they are again diffolved in clean the elixiviated earth and put in water, filtered through a flannel fresh, and thus the operation is bag, and boiled up again in a leffer continued as long as the boiling of boiler to a requisite thickness, and the nitre lafts.
then crystallized again, which · In this decoction of the nitre, brings them to be fit for sale. To what they call the mother of nitre the mother of nitre returned into is absolutely necessary. This is the boiler, they in like manner add the inspissated lixivium remaining more fresh ley from the two great after the cryftallization of nitre, casks, boil it twenty-four hours, which cannot itfelf be made to and then crystallize.
In this mancryftallize : wherefore, this they ner is the work carried on all the keep from one year to the next'; summer, and till the winter's frost and for want thereof, the decoc- puts an end to it. tion must be continued at least One day's produce they call doba, a week before any crystallization amounting in weight to at least can be performed as it ought to one kamien, or fourteen oko, that is, be. The reason of which seems about twenty-four common pounds. to be, that the lixivium is not suf- About one oko, or three pounds, ceptible of a degree of heat fuffi- is lost in the purification. A fincient for sending off the pinguinous gle pound of falt-petre fetches, in and alkaline parts, which neceffary time of war, upon the spot where density is given it by the mother of it is made, four rubles (seventeen nitre, as it contains a copious cal- . shillings) but in time of peace
it is carious earth dissolved in the acid much cheaper. of salt and nitre. When the lixi- Now supposing one carr or four vium, has acquired this pitch, the amphors of loose nitrous earth rest of the operation is easily per- prepared with ashes to make four formed.
cubic feet ; it follows, that from Of this mother of nitre they pour 400 cubit feet of such earth there one or two tubs into the boiler, to may be obtained about 40 pounds which they add the new ley collect. of salt-petre, and that one pound ed in the great casks till the boiler of it resides in ten cubic feet of is full ; then they kindle the fire, prepared earth, or in seven or and keep the contents boiling near eight pounds of the more compact twenty-four hours.
native earth ; though such a comAs foon as they perceive any putation should not be deemed very marks of crystallization on the accurate. surface, they remove the ley thus The earth thus cleared of its decocted and inspissated into the nitre is cast out of the tubs in thirty-two wooden coolers de- heaps about four feet high, and scribed in No. 4, and let it remain fo left for the space of four years, there twenty-four hours ; in which at the end of which the maydan VOL. VII.
are brought thither, and a like cially of iron, it will impart a quantity of nitre is got out of this tincture to the nitre. Hence the earth as before. Upon a third Indian falt-petre is of a reddish working, after seven years more, hue, and the fumes of the aquait still yields fome nitre, but scarce fortis made from it are remarkably enough to defray the cost. red in comparison of those from
I make no doubt but this me- the Polish. This latter, mixed thod of making fait-petre came with English vitriol, yields a hither from the east ; and that it is green aquafortis, which turns a done by a similar process in India precipitated solution of mercury and China. Several authors have yellow, and by cohobation, white. described the method of doing it in In a word, the chemists give the other parts of Europe. They all preference to the Polish salt-petre require earth and allies, and in in all operations. fome, urine and quick lime is em- Nitre may be purchased at a ployed. The mixture is exposed much easier expence by the English, to the air in all of them either Dutch, Poles, and Russians, than it open or under sheds. Some throw can be made for at home; the it up in heaps, others deposit it in reason of which is the cheapness of pits ; which ever way it is done wood-fuel, which may be had, in it infallibly produces nitre, though a manner, for fetching. In the in very different quantities, and Prussian dominions' alone, there is that chiefly, in proportion to the perhaps more falt-petre made than fatness of the earth.
in all Europe besides; and yet I Salt-petre is considerably differ- do believe that scarce a thousandth ent as to its degree of purity. part of what was consumed in the The natural sort of the first de- late wars was of European procoction always holds a portion of duce. Earths rich in volatile salt common falt. Its crystals are not and nitrous particles turn to far prismatic, but cubic, and it is better account in manuring land much of the fame goodness as that and feeding the inhabitants, than which has a mineral alkaline bafis, in furnishing destructive falt-petre, whether from common salt or other. which ought rather to be fought wise ; for it assumes its figure al. after in barren desarts. ways from an alkali, not from an acid, notwithstanding Dr. Linnæus has founded good part of his system of fossils on this error. If too much Process for making Sal Nsirabile: calcarious earth and too little ashes by Mr. Fergus, of Piccadilly. be combined in the decoction, the crystals will not be so hard, and AKE calcined kelp, any if dillolved, may be precipitated quantity, powder it in an by an alkali, which good nitre iron-mortar, put it in an earthen will not submit to. If the ashes pan well glazed, and pour upon be from hard wood, the crystals it boiling water, in the proportion will be firmer and larger, as are of a quart to a pound : ftir it those of India. If the earth has about for a little time, and either any metallic intermixture, elpe- filtrate or decant the clear li
quor from the sediment : put the bridges in China look more like clear liquor in a' glazed earthen fables than realities. dish, place it over a gentle fire, The building of this bridge is and when hot, pour in gradually well worth recording About 12
: oil of vitriol diluted (viz. to every or 14 years ago William Edward, pound of oil of vitriol a pint and a country mason, a native of the a half of water) till no efferves- patish of Eglwyfilan in that councence arises, and you have gained ty, agreed with the hundreds of the exact point of saturation : Miskin and Singhenith to build then filtrate through paper, or a bridge over the river Taaf in let it stand to depurate, and de- four arches for 5001. and to give cant the clear liquor ; evaporate
securities to insure it for seven to a pellicle, and set it by to cryf- years. This bridge was finished, tallize.
but a great flood in this rapid By the above process I obtained river entirely carried it away in from a pound and a half of kelp, less than two years time. He was eight ounces and a half of faithen obliged to begin again. But
. mirabile ; and found that some- he thought with himself that if he thing less than two ounces of oil. could build a bridge in one arch, vitrioli was sufficient for the satura- it would be out of the power of tion.
the flood to hurt him a second N. B. Sal mirabile may be also time ; and he was positive in his made from barilla instead of kelp ; own mind that it was practicable. but not fo cheap.
When he made this proposal to his securities they looked upon it
as a very whimsical scheme ; howAn account of a very remarkable ever at last they consented, and Bridge in Wales.
he fet about it with all the eager
ness of a projector. ; But when he THIS bridge is called by the had almost finished the arch, the
natives Point y ddy prydd. center timber work gave way, and It lies on the river Taaf, at Lan. all fell to the bottom. trissant, near Llandaff, about ten He now began again, erected miles above Cardiff, in Glamor- stronger timber work, fairly comganshire. This bridge is no more pleted the arch, the center was than 8 feet broad, but it consists knocked off, and it stood, the of a single arch no less than 140 wonder and amazement of all befeet wide, part of a circle of 175 holders ; and persons of curiosity feet diameter, fo as to make the al- came to see it from several distant titude 35 feet. It is therefore 40
parts of the kingdom. This was feet wider than the celebrated Ric in the year 1755, when a copperalto of Venice, and probably the plate plan, and prospect of this wideft arch in Europe, if not in furprising arch were published, the world : at least I never read dedicated to Lord Windsor, the of any thing equal to it, that can lord of these manors. But the be relied upon as matter of fact. misfortunes of the poor mason The accounts given by some of were not yet over.
He was no the Popish millionaries of some master of the rules of architec