west; since it appears, that it did not reach our island till the 7th century; when it was brought hither from France, either by Benedict abbot of Winal, or Wilfrid archbishop of York; as lanterns of horn were introduced by King Alfred about the same time, viz. 680.

XXIV. A Description of the Cepphus.* By D. Lysons, M. D. p. 135. This bird is the cepphus of Aldrovandus, though it does not agree in all points: perhaps that which he saw might be a male, this a female.' In his the sides of the mandibles were of a dusky red, in this not. The eyes of his were partly red, which was not observed in this. Round the eyes in his was a whitish circle, in this a variegated semicircle. The legs and shanks in his greenish, in this of a dilute blue. The feet, and membranes connecting the toes, in his were dusky, in this partly black.

XXV. Extract from the Register of the Parish of Holy Cross in Salop, from Michaelmas 1750 to Michaelmas 1760. Communicated by Robert More, Esq., F. R. S. p. 140.

Baptized, males 168; females 163; in all 331. Buried, males 137; females 153; in all 290.

XXVI. An Account of the Earthquake at Lisbon, March 31, 1761: in a Letter from thence, dated April 2, 1761. p. 141.

This earthquake happened the 31st, precisely at 12 o'clock, and lasted full 5 minutes, with a smart and equal vibration. It exceeded all the others, except that of Nov. 1, 1755. It was attended with no other consequences but that of alarming the inhabitants, throwing down some ruins, and rending some houses. About an hour and a quarter afterwards, the sea began to flow and ebb, about 8 feet perpendicular, every 6 minutes, and continued till night. Some small shocks were felt before and after, but of no moment.

XXVII. Another Account of the same Earthquake; in a Letter from Mr. Molloy, dated there April 3, 1761. p. 142.

In this letter there are but few additional circumstances. The shock seemed to Mr. M. to spring from the bowels of the earth, and the motion to be directly up and down. It is the general opinion that if it had run from west to east, or from any quarter of the globe to the other, as the great one the 1st of November 1755 did, there would not have been a house left standing in this unfortunate

This species is the larus crepidatus of the Gmelinian edition of the Systema Natura, and the black-toed gull of Pennant and Latham. Its specific character is thus given by Latham. Larus luteo fuscoque varius subtus pallidior, macula alarum alba.

place, as all the gentlemen that reside here say, it was more severe and constant for the time than the former. Many buildings have tumbled down, but few. people were killed. The earth groaned in so dreadful a manner, that we expected every moment it would open, and swallow this place and all its inhabitants. We have had several slight shocks since, and one this morning about 2 o'clock, which was very severe; our house shook like a bull-rush. There was another more slight about 5.

XXVIII. A Further Account of the Case of William Carey, whose Muscles began to be Ossified. By the Rev. Wm. Henry, D. D., F. R. S. p. 143. In March 1759, I had this young man brought up to Dublin, and admitted into Mercer's hospital. The physicians and surgeons put him under a salivation; and afterwards applied to his arms and joints mercurial plasters. The good effects of this process, was the drying up the great discharge of humour, which he had at his elbows and wrists, and an immediate check to the progress of the ossification. In June following he was discharged from the hospital, being furnished with mercurial plasters and directions. By the advice of the physicians, he went to his own place near Ballyshanon, on the western ocean; and there, in pursuance of their directions, bathed in the ocean twice a day, during that whole summer and harvest, and constantly rubbed his whole body and limbs over with the juice of the quercus marina, immediately after coming out of the sea. In consequence of this course, he happily exchanged his ghastly hectic countenance for a healthy and athletic complexion, which continued till March 1760. About this time his cough returned, his sores began to run, and the ossification to return. In this distress he came to me to Dublin. With some difficulty got him admitted again into Mercer's hospital, where he continued for some months, and was again treated with mercurial medicines and applications as before. After being discharged, he returned to his former course of bathing in the ocean, and anointing his body with the quercus marina. This process restored his health, and entirely stopped the progress of the ossification. He also recovered the use of some of the ossified joints, particularly of his wrists and fingers; and his knees and legs were so relaxed by the dissolution of the callus, that he was able to walk 20 miles in a day.

I

I feared that his disorder might return this spring, as it did in 1760, but it has not returned. That I might be the better certified, I wrote to Sir James Caldwell. The answer I received was, that he had been a few days ago at Castlecaldwell, and found himself so well and strong, as to importune Sir James to admit him into his body of the Enniskillen lighthorse. The poor man thinks the ossification entirely stopped; yet by the appearance of his arms and wrists he seems to be mistaken. The first hardness still continues, and all the muscles

from his elbow to the wrist seem to be one solid bone. It is very happy for him. that it has been hitherto stopped from proceeding any farther; and that from his present state of good health, there is reason to hope that it will not increase.

XXIX. Description of a new Thermometer and Barometer. By Keane Fitzgerald, Esq., F. R. S. p. 146.

Mr. F. lately communicated a paper, with an account of an instrument, intended to answer in some measure the purposes of a thermometer and pyrometer. The degrees the index had pointed to, during the absence of an observer, were marked by a pencil applied to it. But he found great inconvenience from the friction of the pencil, which must be strong, or it does not mark distinctly; besides the trouble of rubbing out the mark, every time a new observation was intended. He now offers the description of an instrument on the same principle as a thermometer only, with registers to mark the least variation that can happen during the absence of an observer; but too complex to be useful.

XXX. Of the Earthquake* felt in the Island of Madeira, March 31, 1761. By Thomas Heberden, M. D., F. R. S. p. 155.

In the city of Funchal, on the island of Madeira, March 31, 1761, they were alarmed with the shock of an earthquake, preceded by the usual noise in the atmosphere, like heavy carriages passing hastily over rough pavements. It began at 35 minutes after 11 o'clock in the morning, and lasted, by the watch, full 3 minutes; the vibrations, which were very quick, remitting and increasing twice very sensibly during the shocks, which seemed to be progressive, from east to west. It has separated some rocks in the eastern part of the island, which have fallen from the cliffs into the sea. It has likewise damaged the walls of several buildings; particularly such walls as stand in a direction north and south.

During the earthquake the fountain of the city, the water of which is very clear at other times, ran turbid and whitish. The sea was agitated very sensibly, fluctuating several times between high-water and low-water mark. The fluctua tion of the sea continued longer in the eastern parts of the island than in this part. The sun, which shone very bright before, immediately after the earthquake was surrounded by a very large halo, which lasted about an hour, and gradually disappeared.

XXXI. An Account of a Treatise in Latin, presented to the Royal Society, entitled De Admirando Frigore Artificiali, quo Mercurius est Congelatus, Dis

See the account of the same earthquake felt at Lisbon, p. 541..

sertatio, &c. a J. A. Braunio, Academiæ Scientiarum Membro, &c. By Wm. Watson, M. D., R. S. S. p. 156.

Very early last year, we were informed, says Dr. W., that at Petersburg, by the means of artificial cold, the mercury in thermometers had been condensed to so great a degree as to become perfectly fixed and solid; but as this information was received only in a loose way from the public gazettes, the opinions of philosophers here were suspended, in regard to their giving credit to this very extraordinary phenomenon, till the truth of it could be sufficiently authenticated. This has lately been done by professor Braun, who first made the experiments,. and who presented an account of them to the Royal Academy at Petersburg. Professor Braun observes, that every age has its inventions, and that the discovery of some things seem to be reserved for particular persons. To this, the history of sciences in all ages, more particularly of the late and the present, bears witness sufficiently, by the invention of the air-pump, barometers, thermometers, optical instruments, electricity, more particularly the natural, artificial magnets, phosphorus, the discovery of the aberration of light, and of many other things in natural philosophy. He does not know whether the congelation of mercury, which it was his good fortune to discover, may not be ranged among these: for who did not consider quicksilver as a body which would preserve its fluidity in every degree of cold? Neither was the fact otherwise, if this is understood of natural cold, such as it has been found in any part of the globe hitherto discovered. But if it should happen that the natural cold should ever be so intense as artificial cold has been found to be, the whole globe would have a different face, as men, animals, and plants, would certainly be destroyed. He hinted some time since, in a dissertation on the degrees of heat which certain liquors and certain fluids would bear before they boiled, and the degrees of cold they respectively bore, before they were converted into ice, that there was a suspicion, that the mercury in some of the barometers and thermometers made use of for experiments in Siberia, had been frozen; but since that in greater degrees of cold, the mercury continued fluid in other barometers and thermometers, the immobility and hardness observed in some of these instruments was attributed more probably to the lead of the bismuth, with which the mercury, had been adulterated, and was not considered as a real freezing of the mercury, but this has been since put out of all doubt, since it is certain, that pure mercury would not freeze under such small degrees of cold, great as they were for natural cold. The experiments which the Professor made, in order to congeal mercury, demonstrate this most evidently, besides which they exhibit new phenomena.

There happened at Petersburgh, on the 14th of December 1759, a very great frost, equal, if not more intense than any which had been observed there for between 9 and 10 o'clock in the morning, Delisle's thermometer stood at 205;

at 7 o'clock at 201; which last was the greatest degree of cold that had been observed at Petersburg either by himself or others. At 1 o'clock at noon, the thermometer stood at 197. Mr. Braun had been employed several days before this, in observing the several degrees of cold which different fluids would bear, before they were converted into ice; partly to confirm those things which he had already laid before the academy, and partly to make experiments on liquors which had not yet been examined; as on the days between the 7th and 14th the cold was intense enough to be between the degrees of 181 and 191. When the natural cold was so intense as to be at 205, Professor Braun conjectured, that it was of all others the most proper occasion to try the effects of artificial cold, not doubting but that artificial cold would be increased in proportion as the natural was more intense. Aquafortis, which was found by the thermometer to be 204 degrees cold, was the greatest part of it frozen, the ice having the appearance of crystals of nitre, which however immediately dissolved in a small degree of heat. This aquafortis which, though frozen at the sides, was liquid in the middle, was poured on pounded ice, in that proportion which was directed by Fahrenheit, the first person who made artificial cold with spirit of nitre. But before the Professor made this experiment, he by examination found, that both the ice and aquafortis were of the temperature with the air, which was then 204. On the first pouring, the mercury fell 20 degrees; this spirit was poured off, and fresh put on several times; but it was possible by these means to introduce no more than 30 degrees of cold: so that the mercury in the thermometer fell no lower than 234. Since therefore Fahrenheit could not produce cold greater than that of 40 below the cypher of his thermometer, which corresponds with 210 of that employed by Professor Braun; nor Reaumur, nor Muschenbroek, who often repeated the same experiment, our author was on the point of giving up this pursuit, as considering this as the greatest degree to which artificial cold could be carried; thinking it sufficient honour to himself to have added 20 degrees to the cold formerly known.

But reflecting that this was not all the fruit he expected from these experiments, he determined to pursue them; but at the same time however to vary the manner of them. By good fortune his ice was all gone, and he was compelled to use snow in its stead, after having first tried, and found the snow of the same degree of cold with the air, at this time 203. The snow, the thermometer, and the aquafortis, being of the same temperature, he immersed the thermometer in snow contained in a glass; and at first only poured a few drops of the aquafortis on that part of the snow in which the thermometer was immersed: on which he observed the mercury to subside to 260. Elated by this remarkable success, he immediately conceived hopes that these experiments might be carried further: nor was he deceived in his expectations; for repeating the ex4 A

VOL. XI.