in natural history, is classed under the genus of Hirundo, under which article the different species have been already described. Concerning this bird, one curious question, however, still remains to be discussed, What becomes of it in the winter? Upon this subject there are three opinions. Some say that it migrates to a warmer climate; winter? Swallow, mate; some, that it retires to hollow trees and caverns, where it lies in a torpid state; and others have affirmed, that it lies in the same state in the bottom of lakes and under the ice. The first opinion is supported by Marigli, Ray, Wil- loughby, Catesby, Reaumur, Adanson, Buffon, &c. The first and second opinion are both adopted by Pennant and White. The third is sanctioned by Scheffer, Hevelius, Derham, Klein, Ellis, Linnæus, Kalm: and the second and third have been strongly defended by the honourable Daines Barrington.

Though we cannot help giving a preference to that opinion which appears the most probable, yet we do not think that any one of them is established upon such evidence as so curious a subject requires, and as the advanced state of natural history would lead us to expect. We shall therefore state the arguments upon which each opinion is founded as fairly and distinctly as we can, and as often as possible in the very words of their respective advocates. By doing so, we shall place the whole subject before the eyes of our readers, who will thus have an opportunity of examining it attentively, and of making such observations and experiments as may lead to the truth.

Those who assert that the swallow migrates to a warm country in winter, argue in this manner: That many birds migrate, is a fact fully proved by the observations of natural historians (see Migration). Is it not more probable, therefore, that swallows, which disappear regularly every season, retire to some other country, than that they lie in a state of torpor in caverns or lakes? But this opinion does not rest on probability, it is founded on facts.

We often see them collected in great flocks on churches, rocks, and trees, about the time when they annually disappear. The direction of their flight has been observed to be northward. Mr White, the ingenious historian of Selborne, travelling near the coast of the British Channel one morning early, saw a flock of swallows take their departure. At the beginning of his journey he was environed with a thick fog; but on a large wild heath the mist began to break, and discovered to him numberless swallows, cluttered on the standing bushes, as if they had roosted there: as soon as the sun burnt out, they were instantly on wing, and with an easy and placid flight proceeded towards the sea. After this he saw no more flocks, only now and then a straggler.

Mr Laffey of Exeter observed attentively the direction which a flock of swallows took in the autumn of 1793. On the 2nd of Sept., about seven o'clock in the morning, the wind being easterly, accompanied with a cold drizzling rain, Mr Laffey's house was entirely covered with house-swallows. At intervals large flocks arrived and joined the main body, and at their arrival an unuful chirping commenced. The appearance of the whole company was so lethargic, that he Gent. Mag. found it an easy matter to catch a considerable number of them, which he kept in a room all that day. By heating the room they all revived: he opened four of them, and found their stomachs quite full. The main body occupied the house top all day, except for two hours. About half an hour after nine on the morning of the 23rd, there was a great commotion, with very loud chirping, and within a few minutes after, the whole multitude took their flight, in a direct south-east direction, having ascended to a great height in the atmosphere. He let go the birds which he had caught, at certain intervals till four o'clock, and they all flew toward the same quarter.

Not only has the direction of their flight been observed, but they have also been found on their passage at a great distance from land. Mr Adanson informs us, that about 50 leagues from the coast of Senegal four swallows settled upon the ship on the 6th of October; that these birds were taken; and that he knew them to be European swallows, which, he conjectures, were returning to the coast of Africa. Sir Charles Wager's authority may also be appealed to: "Returning home (says he) in the spring of the year, as I came into foundings in our channel, a great flock of swallows came and settled on all my rigging; every rope was covered, they hung on one another like a swarm of bees; the decks and carvings were filled with them. They seemed almost famished and spent, and were only feathers and bones; but, being recruited with a night's rest, took their flight in the morning." This vast fatigue proves that their journey must have been very great, considering the amazing swiftness of these birds: in all probability they had crossed the Atlantic ocean, and were returning from the shores of Senegal, or other parts of Africa; so that this account from that most able and honest seaman, confirms the later information of Mr Adanson.

Mr Kalm, who is an advocate for the opinion that swallows lie immersed in lakes during the winter, acknowledges, that in crossing the Atlantic from Europe a swallow lighted on the ship on the 2d September, when it had passed only two-thirds of the ocean. Since, therefore, swallows have been seen assembled in great flocks in autumn flying off in voyage, company towards southern climes, since they have been found both in their passage from Europe and returning again, can there be any doubt of their annual migration? —For Mr Barrington's objections to this opinion, see Migration, p. 5.

The second notion (says Mr Pennant) has great antiquity on its side. Aristotle and Pliny give it as their belief, that swallows do not remove very far from their summer habitation, but winter in the hollows of rocks, and during that in a torpid time lose their feathers. The former part of their opinion has been adopted by several ingenious men; and of late several proofs have been brought of some species, at least, having been discovered in a torpid state. Mr Collinson favoured us with the evidence of three gentlemen, eye-witnesses of numbers of land martins being drawn out of a cliff on the Rhine, in the month of March 1762. And the honourable Daines Barrington communicated to us the following fact, on the authority of the late Lord Belhaven, That numbers of swallows have been found in old dry walls and in sandhills near his Lordship's seat in East Lothian; not once only, but from year to year; and that when they were exposed to the warmth of a fire, they revived. We have also heard of the same annual discoveries near Morpeth in Northumberland, but cannot speak of them with the same assurance as the two former: neither in the two last instances are we certain of the particular species.

"Other witnesses crowd on us to prove the residence of those birds in a torpid state during the severe season. First, in the chalky cliffs of Sussex; as was seen on the fall of a great fragment some years ago. Secondly, In a decayed hollow tree that was cut down, near Dolgelli, in Merionethshire. Thirdly, In a cliff near Whitby, Yorkshire; where, on digging out a fox, whole bushels of swallows were found in a torpid condition. And, lastly, The reverend Mr Conway of Sychton, Flintshire, was so obliging as to communicate the following fact: A few years ago, on looking down an old lead-mine in that county, he observed numbers of swallows clinging to the timbers of the shaft, seemingly asleep; and on flinging some gravel on them, they just moved, but never attempted to fly or change their place: this was between All Saints and Christmas."

These There are doubtless the lurking places of the later hatches, or of those young birds which are incapable of distant migrations. There they continue insensible and rigid; but like flies may sometimes be reanimated by an unseasonable hot day in the midst of winter; for very near Christmas a few appeared on the moulding of a window of Merton college, Oxford, in a remarkably warm nook, which prematurely set their blood in motion, having the same effect as laying them before a fire at the same time of year. Others have been known to make this premature appearance; but as soon as the cold natural to the season returns, they withdraw again to their former retreats.

The above are circumstances we cannot but assent to, though seemingly contradictory to the common course of nature in regard to other birds. We must, therefore, divide our belief relating to these two so different opinions; and conclude, that one part of the swallow tribe migrate, and that others have their winter-quarters near home. If it should be demanded, why swallows alone are found in a torpid state, and not the other many species of soft-billed birds, which likewise disappear about the same time? reasons might be assigned.

The third opinion we shall state and support in the words of Mr Kalm. "Natural history (says he), as all other histories, depends not always upon the intrinsic degree of probability, but upon facts founded on the testimony of people of noted veracity.—Swallows are seldom seen sinking down into the water; swallows have not such organs as frogs or lizards, which are torpid during winter; ergo, swallows live not, and cannot live, under water.—This way of arguing, I believe, would carry us, in a great many cases, too far: for though it is not clear to every one, it may however be true; and lizards and frogs are animals of a class widely different from that of birds, and must therefore of course have a different structure; hence it is they are clasped separately. The bear and the marmot are in winter in a torpid state, and have, however, not such organs as lizards and frogs; and nobody doubts of their being, during some time, in the most rigid climates, in a torpid state: for the Alpine nations hunt the marmots frequently by digging their holes up; and find them so torpid, that they cut their throats, without their reviving or giving the least sign of life during the operation; but when the torpid marmot is brought into a warm room, and placed before the fire, it revives from its lethargy. The question must therefore be decided by facts; nor are there wanting here. Dr Wallerius, the celebrated Swedish chemist, informs us, That he has seen, more than once, swallows assembling on a reed, till they were all immersed and went to the bottom; this being preceded by a digre of a quarter of an hour's length. He attests likewise, that he had seen a swallow caught during winter out of a lake with a net, drawn, as is common in northern countries, under the ice; this bird was brought into a warm room, revived, fluttered about, and soon after died.

Mr Klein applied to many farmers-general of the king of Prussia's domains, who had great lakes in their districts, the fishery in them being a part of the revenue. In winter the fishery thereon is the most considerable under the ice, with nets spreading more than 200 or 300 fathoms, and they are often wound by screws and engines on account of their weight. All the people that were questioned made affidavits upon oath before the magistrates. First, the mother of the countess Lehndorf said, that she had seen a bundle of swallows brought from the Frische-Haff (a lake communicating with the Baltic at Pillaw), which, when brought into a moderately warm room, revived and fluttered about. Secondly, Count Schileben gave an instrument on stamped paper, importing, that by fishing on the lake belonging to his estate of Gerdanen in winter, he saw several swallows caught in the net, one of which he took up in his hand, brought it into a warm room, where it lay about an hour, when it began to stir, and half an hour after, it flew about in the room. Thirdly, Farmer-general (Amtman) Witkowski made affidavit, that, in the year 1740, three swallows were brought up with the net in the great pond at Diddelken; in the year 1741 he got two swallows from another part of the pond, and took them home (they being all caught in his presence); after an hour's space they revived all in a warm room, fluttered about, and died in three hours after. Fourthly, Amtman Bonke says, that having had the estate of Klefskow in farm, he had seen nine swallows brought up in the net from under the ice, all which he took into a warm room, where he distinctly observed how they gradually revived; but a few hours after they all died. Another time his people got likewise some swallows in a net, but he ordered them to be again thrown into the water. Fifthly, Andrew Rutta, a master fisherman at Oletsko, made affidavit, in 1747, that 22 years ago, two swallows were taken up by him in a net, under the ice, and, being brought into a warm room, they flew about. Sixthly, Jacob Koehlau, a master fisherman at Stradauen, made affidavit, that, in 1736, he brought up in winter, in a net, from under the ice of the lake at Raltsi, a seemingly dead swallow, which revived in half an hour's time in a warm room; and he saw, in a quarter of an hour after, the bird grow weaker, and soon after dying. Sevently, I can reckon myself (says our author) among the eye-witnesses of this paradox of natural history. In the year 1735, being a little boy, I saw several swallows brought in winter by the fishermen from the river Viftula to my father's house; where two of them were brought into a warm room, revived, and flew about. I saw them several times settling on the warm stove (which the northern nations have in their rooms); and I recollect well, that the same forenoon they died, and I had them, when dead, in my hand. In the year 1754, after the death of my uncle Godfroy Wolf, captain in the Polish regiment of foot-guards, being myself one of his heirs, I administered for my co-heirs several estates called the Starogly of Dichtau, in Polish Prussia, which my late uncle farmed under the king. In January, the lake of Lybshaw, belonging to these estates, being covered with ice, I ordered the fishermen to fish therein, and in my presence several swallows were taken, which the fishermen threw in again; but one I took up myself, brought it home, which was five miles from thence, and it revived, but died about an hour after its reviving.

These are facts attested by people of the highest quality, by some in public offices, and by others who, though of a low rank, however, made these affidavits upon oath. It is impossible to suppose indiscriminately that they were prompted, by views of interest, to assert as a fact a thing which had no truth in it. It is therefore highly probable, or rather incontestably true, that swallows retire in the northern countries, during winter, into the water, and stay there in a torpid state till the return of warmth revives them again in spring. The question therefore, I believe, ought for the future to be thus stated: The swallows in Spain, Italy, France, and perhaps some from England, remove to warmer climates; some English ones, and some in Germany and other mild countries, retire into crevices and holes in rocks, and remain there in a torpid state. In the colder northern countries the swallows immerse in the sea, in lakes, and rivers; and remain in a torpid state, under ice, during winter. There are still some objections to this latter after- Swallow. assertion, which we must remove. It is said, Why do not rapacious fish, and aquatic quadrupeds, and birds, devour these swallows? The answer is obvious; swallows choose only such places in the water for their winter-retreat as are near reeds and rushes; so that sinking down there between them and their roots, they are by them secured against the rapacities of their enemies. But others object, Why are not these birds caught in fresh waters as are continually harried by nets? I believe the same answer which has been made to the first objection will serve for this likewise. Fishermen take care to keep off with their nets from places filled with reeds and rushes, for fear of entangling and tearing their net; and thus the situation of swallows under water, is the reason that they are seldom disturbed in their silent winter-retreats. What confirms this opinion still more is, that swallows were never caught in Prussia according to the above-mentioned affidavits, but with those parts of the net which passed near to the reeds and rushes; and sometimes the swallows were yet fastened with their feet to a reed, when they were drawn up by the net. As to the argument taken from their being too long under water without corruption, I believe there is a real difference between animals suffocated in water and animals being torpid therein. We have examples of things being a long time under water; to which we may add the intense cold of those northern regions, which preserves them. Who would have thought that snails and polyps might be dried, and could reproduce the parts severed from their bodies, if it was not a fact? Natural history ought to be studied as a collection of facts, not as the history of our guesses or opinions. Nature varies in an infinite manner; and Providence has diversified the instinct of animals and their economy, and adapted it to the various seasons and climates.

With Mr Kalm's concluding observations we heartily concur. Natural history ought to be studied as a collection of facts; and it was from this very notion that we have stated the above mentioned opinions so fully, and brought together the facts which the best advocates for each opinion have judged most proper for supporting them. We are sensible of the great improbability of the third opinion, and know that many arguments have been used to prove its absurdity; such as these, The swallow is lighter than water, and therefore cannot sink; if it mounts at all, it must mount under water during its torpid state, which is very improbable; there is no instance of land animals living so long under water without respiration. Many other arguments of the same sort have been advanced, and certainly afford a short way of deciding the question; but unless they were sufficient to prove the immersion of swallows a physical impossibility, they are of no force when opposed to the evidence of testimony, if there be no cause to suspect the witnesses of inaccuracy or design. The true way to refute such an opinion is by accurate observation and experiment. We have not heard of any accurate inquiries being made by philosophers in those northern countries where swallows are said to pass the winter under water. The count de Buffon, indeed, shut up some swallows in an ice-house by way of experiment, which died in a few days; but as he does not tell us what precautions he took to make the experiment succeed, it is not intitled to any attention.

Mr John Hunter made a very judicious experiment on the banks of the Thames, which is described by a correspondent in the Gentleman's Magazine, who affirms that he had it from Mr Hunter himself.

One year in the month of September, he prepared a room, with every accommodation and convenience which he could contrive, to serve as a dormitory for swallows, if they were disposed to sleep in winter. He placed in the centre a large tub of water with twigs and reeds, &c., which reached to the bottom. In the corners of the room he contrived artificial caverns and holes, into which they might retire; and he laid on the floor, or suspended in the air, different lengths of old wooden pipes, which had formerly been employed in conveying water through the streets, &c.

When the receptacle was rendered as complete as possible, he then engaged some watermen to take by night a large quantity of the swallows that hang upon the reeds in the Thames about the time of their departure. They brought him, in a barge, a considerable number; and had so nicely hit the time of their capture, that on the very day following there were none to be seen.

He put the swallows into the room so prepared, where they continued to fly about, and occasionally perch on the twigs, &c. But not one ever retired into the water, the caverns, holes, or wooden pipes, or shewed the least disposition to grow torpid, &c. In this situation he let them remain till they all died but one. This, appearing to retain some vigour, was set at liberty; when it mounted out of sight, and flew away. All the birds lay dead scattered about the room; but not one was found asleep or torpid, or had, if the correspondent remembers, so much as crept into any of the receptacles he had so provided.

This experiment was ingenious, and certainly does render the doctrine of immersion much more improbable; but it is not decisive; for it may well be urged by the advocates for that doctrine, as Mr Kalm has done, that it may only be in the colder countries where swallows retire into the water. We formerly said that none of the three opinions are supported by such evidence as to satisfy the mind completely. Opinions which respect events which happen every year ought to be confirmed by a great number of observations, and not by a few instances divested of almost all their concomitant circumstances. Can no better proofs be brought to prove the migration of swallows than those of Adanson and Sir Charles Wager, or the circumstances mentioned by Mr White and Mr Larky respecting their disappearing? We ought not merely to know that some swallows have taken a southerly flight in autumn, that some have been found at a great distance from land in the spring, or in harvest; but we ought to know to what countries they actually retire. Before we can rest satisfied, too, that it is a general fact that swallows remain in a torpid state during winter, either in caverns or in the bottom of lakes, &c., we must have more proofs; we must know what species of swallows they are said to be, in what countries this event takes place, and several other circumstances of the same kind.

We cannot help being of opinion that much remains to be done in order properly to ascertain what becomes of the swallows in Europe during winter. It would be necessary, in the first place, to know accurately what are the countries in which swallows are found. 2. Do they remain viable throughout the whole year? Or, if they disappear, at what season does this happen, and when do they appear again? 3. Do they ever appear while a strong north wind blows, or do they only come in great numbers with a south wind? We will endeavour to answer some of these questions in part; but must regret, that all the information on this subject which we have been able to cull from the best writers in natural history is very scanty; and we merely give it by way of specimen, hoping that future observations will soon render it more complete.

There are five species which visit Britain during the summer months; the common or chimney swallow, the martin, sand martin, swift, and goot-sucker. The chimney swallow frequents almost every part of the old continent; being known (says Dr Latham) from Norway to the Cape of... of Good Hope on the one side, and from Kamtschatka to India and Japan on the other. It is also found in all parts of North America, and in several of the West Indian Islands. In Europe it disappears during the winter months. It appears generally a little after the vernal equinox; but rather earlier in the southern, and later in the northern latitudes. It adheres to the usual seasons with much regularity; for though the months of February and March should be uncommonly mild, and April and May remarkably cold, it never deviates from its ordinary time. In the cold spring of 1740 some appeared in France before the insects on which they feed had become numerous enough to support them, and great numbers died. In the mild and even warm spring of 1774 they appeared no earlier than usual. They remain in some warm countries the whole year. Kolben affirms that this is the case at the Cape of Good Hope; but (he says) they are more numerous in winter. Some birds of this species live, during winter, even in Europe; for example, on the coast of Genoa, where they spend the night in the open country on the orange shrubs.

2. The martins are also widely diffused through the old continent; but the countries where they reside or visit have not been marked by naturalists with much attention. 3. The sand martins are found in every part of Europe, and frequently spend the winter in Malta. Two birds of this species were seen in Perigord in France, on the 27th December 1775, when there was a southerly wind, attended with a little rain. 4. The swift visits the whole continent of Europe; has also been observed at the Cape of Good Hope, and in Carolina in North America. 5. The goatsuckers are not very common birds, yet are widely scattered. They are found in every country between Sweden and Africa; they are found also in India. In April the south-west wind brings them to Malta, and in autumn they repose in great numbers.

Mr Markwick of Catsfield, near Battle in Sussex, has drawn up an accurate table, expressing the day of the month on which the birds, commonly called migratory, appeared in spring, and disappeared in autumn, for 16 years, from 1768 to 1783 inclusive. The observations were made at Catsfield. From this table we shall extract the dates for five years, and add the very few observations which we have been able to collect respecting the time when the swallow appears and disappears in other countries.

| Year | Month | Day | |------|-------|-----| | 1779 | Feb. | 15 | | | Mar. | 15 | | | Apr. | 15 | | | May | 7 | | | June | 9 | | 1780 | Nov. | 5 | | | Dec. | 29 | | | Jan. | 29 | | | Feb. | 29 | | | Mar. | 29 | | | Apr. | 29 | | | May | 6 | | 1781 | Aug. | 15 | | | Sep. | 7 | | | Oct. | 15 | | | Nov. | 15 | | | Dec. | 15 |

Were tables of the same kind made in every different country, particularly within the torrid zone, it would be easy to determine the question which we have been considering. To many, perhaps, it may not appear a matter of such importance as to be worth the labour. We acknowledge it to be rather a curious than an important inquiry; yet it is one which must be highly gratifying to every mind that can admire the wisdom of the Great Architect of nature. The instinct of the swallow is indeed wonderful: it appears among us just at the time when insects become numerous; and it continues with us during the hot weather, in order to prevent them from multiplying too much. It disappears when these insects are no longer troublesome. It is never found in flocks; it is the friend of man, and always takes up its residence with us, that it may protect our houses and our streets from being annoy- ed with swarms of flies.

SWALLOW-Wort, in botany. See ASCLEPIAS.