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than ever known, and was attended by frosts. The sky was always hazy, calm, and dry ; the wind always from the south. This extended over the first twelve degrees of south latitude. But the climate of New Grenada is subject to severe frosts at night, even during the season of most scorching heat. The inhabitants of the country desolated by the earthquakes at Pasto, &c., in January, 1834, suffered from this most dreadfully. Towards the end of August, 1804, the maize in New Mexico was so completely destroyed by intense frosts, that famine, and its attendant pestilence, carried off no less than 300,000 persons. Now, 1804 was a close season, when little ice was melted in the Atlantic; and the same may be said of 1809. Were these frosts caused by ice in the Atlantic? Yet, why not P Again, are the horrid frosts in Persia and China, and in Africa (12° N.), caused by this melted polar ice? As has been well observed by M. Parrot, the cooling of the sea, by the melting of the ice, would be like cooling Geneva Lake with a cubic fathom of water of the temperature of melting ice; and to cool Europe this way would be still more preposterous.* M. Parrot is contending against Fourrier's theory of a central fire; and says, in continuation, that, if such a fire exists, it would be proved by the increased temperature of the sea at great depths. He proves that the temperature at sea decreases with the depth ; and alludes to Mr. Scoresby's experiments in the deep sea between Greenland and Spitzbergen, where the heat increased even amidst ice; and justly observes, that this heat was owing to the volcanic mass below.} M. Parrot rejects in toto the idea of a central heat; and considers that all the phenomena connected with terrestrial heat arise from volcanic action, which has existed from the earliest times; and still operates, though with much less intensity than at ancient eras. In this case I am completely borne out in my speculations by M. Parrot. Notwithstanding, in the above remarks, I am far from wishing to deny any indubitable influence that the ice may have in producing sudden paroxysms of cold in the direction of the wind blowing across it. The chill, in the spring of 1833 and 1834, and, perhaps, an occasional coldness since, were, as I believe, occasioned by the wind bringing to our shores a stratum of “raw moist air:” but I dispute that the ice was the cause of the wind's direction ; the point I am endeavouring to explain. Navigators all state, that, in approaching the ice, the temperature falls; and that variable and gusty whirlwinds attend it: they give no idea of a constant breeze from the west. So far, then, I allow, and no farther, the melting of ice in the Atlantic to be a means of cooling our atmosphere: and this melting of the ice is, it is almost certain, the effect of terrestrial heat; so that even our “raw, moist, chilly” weather is attributable to the same cause as the dry hot atmosphere which has so recently prevailed. Paradoxically, this is to maintain that heat may produce cold; but cold can never produce heat. I will, in my next paper, consider the question more fully. Clifton, Oct. 13, 1834.
* Considérations sur la Température du Globe, &c. (Mémoires de I'Académie de St. Petersbourg.) There is a paper on the same subject, by the same author, in the Bulletin de Férussac. + Vide Quarterly Review, xviii. 452–3, where are some sensible remarks on this subject. See, also, De la Beche, Manual of Geology, p. 22.
ART. II. Observations on some of the Diseases in Poultry. By J. M. Coby, Esq., Member of the Royal College of Surgeons in London, of the Provincial Medical and Surgical Association, of the Medical and Philosophical Society of London, &c.
As the diseases of the feathered tribe have not hitherto attracted much scientific attention in this country, it may not be uninteresting to the readers of the Magazine of Natural History to be presented with a few facts and investigations deduced from the study of comparative morbid anatomy. The pathology of birds had been slightly entered upon by Mr. Youatt, the highly talented professor of veterinary medicine at the London University; and it is to be regretted that his researches, which appear to have been confined to more valuable animals, have not been extended in this department. The naturalist may possibly be able to refer to a nosological system in some of the numerous works on zoology, British or foreign; but I am not aware of the existence of any such system. Girard's Anatomie des Animaur Domestiques, 2 vols. Paris, 1820, which is one of the latest foreign works on the structure of domestic animals, does not, I believe, enter upon the subject of pathology.
1. Cerebral Apoplery or Stroke.—The animal, when attacked with this disease, suddenly falls, appears senseless, and is found with the head bent under the neck or thorax. Every time an attempt is made to place it in a sitting or standing position, the head is constantly forced downwards below the breast, the cranium resting on the ground. There is no incli– nation to take food; and, when it is artificially introduced into the pharynx, it passes onward to the crop. In some instances, death rapidly supervenes; in others, some days elapse, when convulsions in the voluntary muscles appear, and continue till life is exhausted. This disease is, I believe, always considered to be fatal; but its nature and remote cause are, I apprehend, little known. I believe, in most, if not all, cases, it is occasioned by some vegetable poison, received into the stomach, which has the effect of exciting an engorgement of the vessels of the brain, and a consequent rupture of one of the veins or sinuses of that organ. On the 31st of August, a fine young hen dropped from her roost almost immediately after she had placed herself upon it. The apoplectic symptoms, above described, were immediately observed ; and, at the end of a week, convulsions of the extremities, and of one or both of the larynges (or vocal organs), took place; and, on the eighth day, she died. She was artificially fed and kept warm during the whole illness, and deglutition was completely effected; but the crop had not discharged any of its contents, which had been thus accumulated within it. On examining the head, I found a rupture of the longitudinal vein or sinus near that part where in the human subject the torcular Herophili is situated; and a considerable quantity of coagulated blood was lying in contact with the cerebellum and medulla oblongata, and forced into the mastoid cells. The gizzard was distended with Irish ivy, which had been picked from a wall covered with it, and bounding the poultry yard. On enquiry, I find that ivy is well known to be poisonous to poultry. Its secondary operation on the vascular system of the brain or cerebellum has probably never been suspected. 2. Emphysema. — Chickens, when about two weeks or three weeks old, are subject to an emphysematous swelling, a collection of air, under the integuments about the neck, generally preceded by a slight morbid sound in the larynx; and accompanied with vertigo, closing of the eyelids, drooping or convulsive motion of the wings, and coldness of the whole body, which ends in death. This is a different disease from the roup, which is designated by a mucous or mucopurulent discharge from the eyelids, mouth, and nasal passages. Dissection presents no morbid appearance in the lungs, or injury in the ribs; and the pharynx, oesophagus, gizzard, and the rest of the alimentary canal, are free from disease; except the ileum, the mucous coat of which I have, in some instances, found in a state of softening (or what the French call ramollissement), readily admitting of abrasion, occasionally attended with perforations; and, in one case, with black marks on the peritoneal coat, opposite the disease in the internal surface. These black marks, of which the annexed is a representation, arise from a species of disorganisation, which is, I believe, peculiar to 4.AAÁAA serous membranes, as I have never observed ATATATATA z them in other structures; and, on that part of the intestinal tube being immersed in water a few hours, they disappear, and leave corresponding semiperforations. I have remarked the same appearance in the human intestines, accompanied with a softening and abrasion of the mucous tunic, and a general disease of a specific character affecting the whole serous covering of the abdominal viscera. The other morbid phenomena consist of a softening, erosion, and partial destruction of the spinal marrow, immediately adjoining the medulla oblongata, accompanied with a considerable effusion of bloody serum, and preternatural vascularity of the adjacent parts.
The extravasation of air is probably produced by the rupture of one of the axillary or thoracic air cells into which the animal has the power of inflating air from the lungs by means of numerous large tubes resembling the respiratory organs of insects. I am disposed to believe that there exists in these cases a direct communication between the cellular membrane infiltrated with air and the lungs; because, whenever I have punctured the integuments, and produced perfect collapse, the swelling and crackling have been speedily and repeatedly restored. I have not been able to trace the exact source from which the air proceeds, as the cells, even in large birds, are of delicate structure, and, in some, extend from the axilla under the skin along the neck; and, in young poultry, they are still more delicate. I hope to be able to ascertain this point, and to direct my enquiries more particularly to the state of the trachea and inferior larynx.
The morbid condition of the spinal medulla and the adjoining medullary structure is sufficient to account for the paralytic and convulsive affections of the upper extremities; but whether this state may be primary or secondary, appears to me at present uncertain. As I am engaged in the investigation of some diseases of the nervous system, which has led me to take advantage of comparative physiology and pathology, I decline at present entering any farther into this important subject.
Bridgnorth, Oct. 15, 1834.
[IN V. 207, 208. are figures and particulars of a species of intestinal worm, of which numerous individuals had been found attached to the inner surface of the trachea (windpipe) of a number of pheasants that had died. In II. 300, 301., are particulars on the conditions of the death of a hen, which had died of strangulation from a lump of cellular substance which had been formed around the trachea immediately above its entrance under the breastbone. In I. 300., and II. 288., are remarks relative to the rearing of young pheasants; and, in the remarks in I. 300., it is noticed that certain young pheasants had died “very suddenly, as they’’ were “throwing out their crop and tail feathers.” The late Rev. L. Guilding had made this note on that fact: —“The destruction of the young pheasants may have proceeded from parasitic lice and acari. In the West Indies, these creatures are fatal; and a single acarus will sometimes kill a full-grown fowl. An account of these pests was sent [by me], with a drawing, to the conductors of the 200logical Journal, several years ago, who have not yet been able to insert it. — L. Guilding. St. Vincent, May 1. 1830.”
ART. III. Information on the Habits of a Species of Caprimūlgus (or of some closely allied Genus) which inhabits the Neighbourhood of Lima. By Mr. ANDREw MAthews, A.L.S., Travelling Collector of Natural Productions in South America.
The specimen sent is one of the male of a species which is common in the vicinity of Lima. It visits this neighbourhood in about the end of October or beginning of November. The female lays her egg (I have not seen more than one) upon the bare ground, without the least sign or preparation of a nest, and at a distance from any vegetation. One which I had watched daily, this last summer, until the young bird had become hatched from it, was laid on a “huaca" (a large heap of stones) planted around the base with grape vines; so that, had the bird preferred privacy, she might have placed her egg where it would have been more secret. The egg is of about the size of a blackbird’s egg, of a dirty white or stone colour, mottled with olive and brownish green of different shades. The young is, at first, covered with a greyish down: as its feathers appear, it assumes the colour and markings of the parent. The female parent, during the period of incubation, is remarkably fearless, and will even suffer the hand to be brought within 2 ft. of her before she will quit her charge. Her colour is so much that of the ground and stones, that she, when sitting, is not readily observed. When she does quit her charge, it is only for the distance of a few yards;