Previous to the relation of the experiments, it is necessary to observe, that the Russian fir-black is three or four times more heavy, thick, and unctuous, than that kind of painter's black which the Germans call kien-rahm. The former is gathered at Ochta, near St. Petersburgh, at Mosco, at Archangel, and other places, in little wooden huts, from resinous fir-wood, and the unctuous bark of birch, by means of an apparatus uncommonly simple, consisting of pots without bottoms, set one upon the other; and is sold very cheap. The famous fine German kien-rahm is called in Bussia Holland's black. In what follows, when I speak of raw oil, it is to be understood of linseedoil, or hemp-oil; but most commonly the latter. The varnish is made of five pounds of hemp-oil boiled with two ounces and a half of minium. For wrapping up the composition, Mr. Georgi made use of coarse hemp linen, and always single, never double. The impregnations and commixtures were made in a large wooden bowl, in which they stood open till they were wrapt up in linen.

That I may not be too prolix, I will select and communicate only such of the experiments as were most remarkable, and succeeded

best.

Three pounds of Russian fir-black were slowly impregnated with five pounds of hemp-oil-varnish; and, when the mixture had stood open five hours, it was bound up in linen. By this process it became clotted; but some of the black remained dry. When the bundle had lain sixteen hours in a chest, it was observed to emit a very nauseous, and rather putrid smell, not quite unlike that VOL. XXXVII,

of boiling oil. Some parts of it became warm, and steamed much; this steam was watery, and by no means inflammable. Eighteen hours after, the mixture was wrapt up, one place became brown, emitted smoke, and directly afterwards glowing fire appeared. The same thing happened in a second and a third place; though other places were scarcely warm. The fire crept slowly around, and gave a thick, grey, stinking smoke. Mr. Georgi took the bundle out of the chest, and laid it on a stone pavement; when, on being exposed to the free air, there arose a slow burning flame, a span high, with a strong body of smoke. Not long afterwards there appeared, here and there, several chaps, or clefts, as from a little volcano, the vapour issuing from which burst into flame. On his breaking the lump, it burst into a very violent flame, full three feet high, which soon grew less, and then went out. The smoking glowing fire lasted for the space of six hours; and afterwards the remainder continued to glow without smoke for two hours longer. The grey earthy ashes, when cold, weighed five ounces and a half.

In another experiment perfectly similar to the foregoing, as far as relates to the composition and quantities, the enkindling did not ensue till forty-one hours after the impreg nation: the heat kept increasing for three hours, and then the accension followed.

It is worthy of remark, that these experiments succeeded better on bright days, than on such as were rainy and the accension came on inore rapidly.

In another, experiment, three pounds of Russian fir-black were [F] slowly slowly impregnated with three pounds of raw hemp-oil; and the accension ensued after nine hours.

Three quarters of a pound of German rahm were slowly impregnated with a pound and a half of hemp-oil varnish. The mixture remained seventy hours before it became hot and reeking. It then gradually became hotter, and emitted a strong exhalation; the effluvia were moist, and not inflammable. The re-action lasted thirty-six hours, during which the heat was one while stronger, and then weaker, and at length quite ceased.

Stove, or chimney soot, mostly formed from birch-wood smoke, was mingled with the above-mentioned substances and tied up; the compound remained cold and quiet.

Russian fir-black, mixed with equal parts of oil of turpentine, and bound up, exhibited not the least re-action or warmth.

Birch-oil, mixed with equal parts of Russian fir-black, and bound up, began to emit a volatile smell; but the warmth soon went off again.

From the experiments of the Admiralty, and of Mr. Georgi, we learn, not only the decisive certainty of the self-accension of soot and oil, when the two substances are mixed under certain circumstances, but also the following particulars.

Of the various kinds of soot or lamp-black, the experiments succeeded more frequently and surely with the coarser, more unctuous, and heavier, like Russian painter's black, than with fine light German rahm, or with coarse chimney-soot. In regard to oils, only those experiments succeeded which were made with drying oils, either raw or boiled. The proportions of the soots to the oils were, in the suc

cessful experiments very various; the mixture kindled with a tenth, a fifth, a third, with an equal, and likewise with a double proportion of oil. In general, however, much more depends on the mode of mixture, and the manipulation; and, as Mr. Georgi often observed, on the weather: for, in moist weather, the bundles, after becoming warm, would frequently grow cold again.

It is in all respects remarkable, that it should never till now have been observed, that a mixture which has been made millions of times, in all proportions and quantities, for painting of ships, and the outside of wooden houses, and sometimes intentionally, sometimes accidentally, left covered or open, a longer or a shorter time, should be capable of kindling of itself. It is highly probable, that, even on this occasion it was entirely owing to the attention of the empress that it was made an object of enquiry, or even that it was at all observed.

Before I finish this paper, I will just mention a self-accension, not noticed till of late, and that by Mr. Hagemann, an apothecary at Bremen. He prepared a boiled oil of hyoscyamus, or henbane, in the usual way, with common oil. The humidity of the herb was nearly evaporated, when he was called away by other affairs, and was obliged to leave the oil on the fire. The evaporation of the humidity was hereby carried so far, that the herb could easily be rubbed to powder. The oil had lost its green colour, and had become brownish. In this state it was on the straining-cloth, and placed in the garden, behind the house, in the open air.

laid

In

In the space of half an hour, on coming again to this place, he perceived a strong smoke there, though he thought the oil must long have been cooled: on closer inspection, he found that the smoke did not proceed from the oil, but from the herb on the straining-cloth; at the same time the smell betrayed a concealed fire.

He stirred the herb about, and blew into it a bellows, whereupon it broke out into a bright flame. Had this herb been placed in the house near the fire, it might easily have been supposed that a spark had flown into it, which had caused the inflammation; but this was not the case; the herb had kindled of itself. We see from this, that those who are entrusted with the preparation of boiled oils, should take care they do not give occasion to dangers by fire, which may excite suspicions of felonious designs, to the ruin of innocent persons in their lives or reputations.

I am, &c.

tains, and which precisely resembles the species given in Buffon's Natural History, part xix. plate 21. French octavo, and in Schreber's Sucking Animals, part iii. plate 109, page 408. But the lynx of Abruzzo is of a darker colour, is from eighteen to twenty inches high, and from twenty-four to twenty-seven inches in length, to the root of the tail, which is four inches long. The male is larger than the female. The colour is whitish, with spots like stars, of a reddish yellow, inclining to a yellow gold colour. The hair is short and soft, the head large, and like a tiger's, with longish upright ears, terminated by a tuft of coarse, hard, and upright bristles. The eyes are large, and the teeth, claws, and whiskers, are long and sharp. Had I been fortunate enough to procure a dead one, I could give a much more complete description; but, I could not succeed in my endeavours. The actions of this animal exactly resemble those of a cat, like which it sits, runs, springs, eats, purrs, and sleeps; although all these actions are in proportion to its superior size. It is easily tamed; and the Barons Tomasetti assured me that it ran about the house like a cat, was much attached to them, and was in no wise inconvenient, except from its extraordinary curiosity. Not a corner in the house, nor a moveable therein, remained unvisited; and a female lost its life by jumping down the hole in the privy. I was surprised to find that the domestic cat had an insuperable aversion to this animal; and I was assured that the moment that alynx was brought into the house, all the cats disappeared, and were seen no more during that animal's abode there. The lynx bears the priva[* F 2] tion tion of its freedom only so long as it is allowed to wander about the house; all those which the Baron sent to the royal menagerie having soon died of excess of fat, which was the case with that I saw there, and which also appeared extremely melancholy. The lynx of Abruzzo is unquestionably the most swift, subtle, and audacious beast of prey in Italy. It only wanders about in the night, and never is seen in the day, unless when in heat, or in search of provision forits young. It feeds upon all kinds of mice, moles, martins, ferrets, hares, badgers, otters, and even sheep and goats; neither are tame and wild fowl safe from its attacks. It watches for its prey, either upon the ground, or between the branches of a tree, and usually seizes it at the very first spring, even though it be on full speed; and from its ambuscade amongst the branches it successfully darts upon birds that are upon the wing. When it has killed such a large animal as a wild boar, or a roebuck, it first sucks the blood out of the arteries, which seems to be its favourite food; after which it devours the soft parts of the head, neck, shoulders, and legs, together with the entrails, and leaves the remainder. When it fails in procuring a live animal, it contents itself with vegetables, or gratifies itself with all kinds of fruit. Its favourite place of abode is amongst thick and extensive forests, and in solitary districts, where it makes its retreat in hollow trees, or in holes and clefts in the rocks. It pairs only once a year, at the beginning of spring; and contrary to the custom of cats, which celebrate their nuptials with hideous cries, it re

She

mains perfectly silent. The female goes two months, and then brings forth two young ones, which are generally of different sexes. suckles them during two months; and the young ones require two years to grow and be fit for pairing. It has been observed here that the lynx generally attains the age of twenty years. Sociability appertains not to its qualities, and more than one couple are rarely found in a district. Like all creatures upon earth, this also has its enemies, and is pursued by men, dogs, wolves, and large snakes. Flight is its first object; but when it is deprived of the means of escape, and is attacked and wounded, it defends itself against every description of enemy, with such fury and dexterity, that it is seldom overcome but by numbers of beasts, or the superiority of human sagacity. The lynx not only feeds occasionally upon the bodies of dead men, but even attacks children and devours them. This animal is seldom to be taken alive, except whilst very young, when it is frequently found playing upon the grass near the trees, or straying about the country in quest of its mother. It is sometimes taken in traps, but is generally shot. The attachment subsisting between a couple is remarkable; for, when one lies dead upon the ground, and the hunters have retired to a certain distance, the other approaches its comrade, looks at it, goes round it, lies down by it, goes away, and returns several times, until it appears to have lost all hopes of its being only asleep. The lynx furnishes man with a very warm and useful skin; and some profit arises from its fat and gall.

USE

1

:

On the use of Sea Water in Agriculture; from the Earl of Dundonald's Treatise on Agriculture and Chemistry.

B

U'r as it may happen that much time may elapse before any relief is granted, or any alteration made in the present salt laws, it becomes important to consider how a supply of salt, or what is still more valuable, how a supply of sea or salt water may be obtained for the use of cattle, and the purposes of agriculture, without being subjected to the present duties. Previous to this explanation, it is proper to state some farther circumstances, more fully to impress on the mind of the farmer the effect which salt or sea water has in promoting the more full putrefaction of dung and vegetable matters. It is well known that ships built of unseasoned timber are at first very unhealthy. The exhalation of the vegetable juices of the fresh wood is not the sole cause. It is principally to be ascribed to the putrescent hepatic gas generated by the mixture of the vegetable juices with the vitriolic neutral salts contained in sea water, forming what is called bilge water. The smell of it is no less offensive, than its effects are prejudicial to the health of the ship's company. When

new vessel happens to be tight,

and to make little water, it is the practice with all intelligent seamen, to sweeten the vessel's hold and limbers, by daily letting in and pumping out a sufficient quantity of

water.

Certain gases, which are injurious to the health of animals, are favourable to the growth of plants: hepatic air is one of them; and as hepatic air is formed in vessels' holds by the action of sea water on the soluble matter of the wood, the same effect will be produced by the addition of salt water to dung or to vegetable matters. The generation of the hepar is to be ascribed solely to the vitriolic salts contained in sea water, and there is some reason to suspect, that sea salt, or muriat of soda, may suffer a decomposition in this putrefactive process, and that the marine acid thereof may be decomposed.

The putrefaction of sea water is not confined to the bilge water in vessels. The water of the sea itself, in certain southern latitudes, undergoes a material change, emitting, during long calms, a putrid offensive smell; and water intended for the purpose of making salt, kept too long in the reservoirs during summer, will suffer such an alteration in its nature, as to be rendered inca, pable of yielding chrystals of sea salt. A month or six weeks of warm