The last paper in the part before us, is from the pen of the late Dr. Godman, and we cannot look upon it as the last memorial of its author, but with mingled feelings of pleasure and regret. With pleasure, as exhibiting another evidence, among the many which history affords, of the acknowledged power of real talent, when combined with an enthusiastic love of knowledge;-of regret, that this respected individual should have found his path through life a constant struggle with adversity and disease; a struggle, which, although it brought him to an early grave, still never was sufficiently powerful to overcome his zeal, or to dampen his pursuit of that reputation, which it was his ambition to obtain in defiance of every difficulty. In Dr. Godman, the youthful votary of science will have an instructive example of the reward of labor and perseverance. Raised by his own exertions from an ordinary situation in life, without friends or education, he succeeded in procuring the first by his character and talents, and acquired the latter by industry and untiring ardor; and, finally, from a printer's boy, elevated himself to the professional chair of Anatomy and Physiology, and spreading the result of his laborious investigations in many departments of science, before learned societies, and through various publications, he has left behind a name, which will long be remembered with respect.

In this paper, Dr. Godman detected a curious fact in the history of the dentition of the great fossil mastedon of this country. The young of this species is furnished with two incisors, or tusks, in the lower jaw, which soon drop out, and the sockets themselves fill up and disappear. Dr. Godman was not aware of this fact himself, but supposed that he had disnew genus. He accordingly proposed for it a new generic and specific appellation, which, of course, must be suppressed. We must, therefore, be still restricted to the knowledge of only four gigantic antediluvian quadrupeds in this continent: the Megalonix, first described by Mr. Jefferson, the Mastedon, the Megatherium, and the Elephant.

To those who are desirous of investigating the subject, we refer to a paper read by Mr. William Cooper before the Lyceum of Natural History, in which the question is examined in great detail, and analogical instances in other quadrupeds are mentioned.

G.

MEDICAL INTELLIGENCE.

ANATOMY AND PHYSIOLOGY.

1. ON the cause of the Entrance of Air into the Veins during Operations on the Neck. (Archives Générales de Médecine, Juin, 1830.)— It is well known, that on several occasions, death has taken place suddenly during surgical operations on the neck, and that the acci dent has been traced to the admission of air into the heart and great vessels, by the mouths of divided veins. But no satisfactory expla nation has yet been given of the fact that such an accident occurs rarely, or of the circumstance that air should ever obtain entrance at all. For, although most physiologists now admit, to a certain extent, the principles laid down by Dr. Barry, as to the venous circulation and the suction-power which is excited during inspira tion on the blood in the veins that enter the chest,-still, as M. Berard, the author of the paper quoted above, has remarked, it is not easy to see how this suction-power should have the effect of drawing air into the cavity of a flaccid vein, the parietes of which must yield to atmospheric pressure before any fluid, even aeriform, can enter by an opening in it. M. Berard, however, has succeeded in explaining the cause of the entrance of the air; and has likewise discovered in this cause an organization of considerable consequence for maintaining the functions of the great veins near the heart.

He observes, that the veins are all formed of extremely flaccid coats; so as to collapse entirely when empty, provided the atmospheric pressure act on their external surface, and that they would consequently be all reduced to a similar state by the suction-power of the heart and chest, unless their calibres were kept open by some peculiarity of mechanism. This peculiarity consists in the adhesion of the parietes of certain veins to adjacent parts, which tend to keep them stretched. Such a structure has been long known to exist in the case of the sinuses of the brain, and ramifications of the venæ hepatica; the former of which are kept constantly distended by the organization of the falx and tentorium of the dura mater, and the latter by the incompressible nature of the organ

through which they are distributed. But M. Berard now calls the attention of physiologists to certain peculiarities in the organization of other veins, for accomplishing the same purpose. The entrance of the superior vena cava into the right auricle of the heart is kept in a state of constant tension by the prolongation over it of the strong fibrous covering of the pericardium; and the subclavian veins, the junction of the jugulars with these veins, as also the whole course of the axillary veins from the scaleni muscles to the arm-pit, are maintained in a similar state, by being attached to various aponeurotic membranes at the root of the neck. Hence, if the superior cava, subclavian, axillary, or commencement of the jugular veins, be divided, they do not collapse as other veins do, but remain gaping, unless they are detached from the texture by which they are kept distended, and then they collapse like veins generally. Were it not for this organization, it is obvious that the suction-power of inspiration, even of the powerful kind which is admitted by some physiologists, could have little or no effect in moving the blood towards the heart along the superior cava. But the chief veins being kept in a state of distension, and so enabled to resist the compressing tendency of atmospheric pressure, the pumping or inspiring power of inspiration becomes effective; and it is particularly worthy of remark, that as the aponeurotic membranes to which the veins are attached extend from bones to bones, and are most stretched during the expansion of the chest,-it is during the act of inspiration that the veins are most extended. The same organization will also, for the same reason, account for the entrance of air into the heart, from wounds of the veins at the root of the neck during surgical operations. If the subclavian, or commencement of the jugular vein, is opened, air will enter to a certainty, unless immediate precautions be taken to exclude it; and as for the same accident occurring when more distant veins are opened, it will be found, we doubt not, to arise from the divided vein having acquired, from connexion with diseased parts, an organization similar to that possessed by the subclavian and axillary veins in their natural state. M. Berard farther observes, that the inferior cava, by its passage through the diaphragm, is similarly organized with the superior cava. It remains constantly extended and gaping, even when empty. Hence the suction effect of inspiration is transmitted to the hepatic veins, which, we have already seen, are fitted for conveying it by a corresponding structure. It is thus apparent, that the inspiratory power of the chest is one of the powers which contribute to the movement of the blood in the vascular system of the liver. The want of a corresponding structure of the great veins leading to the extremities, renders this moving power of no influence whatever on the circulation in the other branches of the inferior cava.-Ed. Med. and Surg. Journal, for Oct., 1830.

2. On the Animal Temperature in different Latitudes. (Anales de Sciences Naturelles, Mai, 1830.)-A few years ago, Dr. John Davy

made some interesting experiments on the differences which take place in the temperature of the human body in passing to warmer or colder latitudes; (Edin. New Philos. Journal.) and the result was, that in warm climates it rises, and in cold climates falls a little. These experiments have been more lately repeated by M. Reynaud, of Paris, during a voyage to the East. The voyage was from Toulon by the Cape to the Isle of Bourbon, the Maldivians, the Coromandel coast, Bengal, the coast of Pegu, Ceylon, the Straits of Junda, Java, and then home by the Cape to Havre; and it lasted from May, 1827,'to December, 1828. The thermometers used were carefully compared by M. Arago with the standard at the Observatory of Paris, both before and after the voyage,-so that the accu. racy of the observations is unquestionable. There are seven sets of experiments, four of which were made in the torrid, and three in the temperate zones, and each set was made on the same twelve men, all of them being in good health, most of them athletic, and all fed and exercised almost precisely in the same manner. On the 1st July, in 10° 4' north latitude, the air being 79° F. the average temperature of twelve Europeans was 9910. On the 10th of August following, in 36 10' south latitude, the air being 621, the average temperature of the body was 983. On the 11th Sep. tember, under the line, with an atmospheric heat of 86°, the temperature of the body was on an average very nearly 100°. Next year on the 13th May, in latitude 7 1'-south, the air being 86°, the body was 98. On the 14th of October following, in 82° 23' south latitude, the air being 624, the body was 99°. On the 30th of October, under the line, with an atmospheric temperature of 79°, that of the body was 99. On the 4th December, in 46° north latitude, the air being 53, the body was 99. Hence it will be perceived, that the range of the animal heat, between climates where 53 and 86 are the extreme temperatures of the atmosphere, is one degree and a quarter of Fahrenheit, and that it rises as the atmospheric heat rises, and vice versa,-with some slight irregu. larities, probably to be ascribed to the coldness or heat of the climate, which the subjects of experiment has just left.—Ibid.

3. On the influence of atmospheric temperature on the Mortality among Infants. (Annales d'Hygiène Publique et de Médecine Légale, Janvier et Avril, 1830.)-MM. Villermé and Mylne Edwards have proved, by a set of statistical tables, that the mortality among young infants is considerably greater in the colder northern departments of France, than in the warm southern departments, and that in the same place it is considerably greater during the cold months of the year than during the temperate months, and also somewhat greater in the hottest months than in those which are temperate. Thus in the northern part of France, situated above the latitude of 49°, the mortality among children within the first three months of life, was in 1818, as 1 to 7.96 births,-south of the 45th degree of latitude it was only as 1 to 10.72; and in 1819 it was in the former district

as 1 to 9.12, and in the latter as 1 to 11.7. At Dunkirk the mean temperature of the year is 11 degrees less than at Toulon, the former being 50.4 F., the latter 62°. Thus again in the year 1818, the mortality for the same period of life throughout the whole of France, varied from one death in 7.22 births, during the month of January, to one in 9.8 in the month of May; and in 1819, from one in 7.66 during January, to one in 9.97 during the month of May. During the three cold months of December, January, and February, the average for the two years, was one in 7.81; during March and April, it was one in 8.78; during May, June, and July, one in 9.75; during August and September, one in 8.06; during October and November, one in 8.68. In order to perceive fully the effects of temperature in producing these variations, the English reader must keep in remembrance, that August and September are in France extremely hot months, while October, and even November, are much more mild than in Britain. The inference to be drawn from the numerical statements here given, as to the mortality in different seasons, is, that in the coldest months it is greatest, in the warm months at the beginning of summer least, but somewhat greater even in the warm months, when the extreme heat of summer has endured for a considerable time.

These facts have been since very satisfactorily confirmed by the statistical inquiries of M. Caffort, at Narbonne, in the middle of France. In the course of fifteen years subsequent to 1810, the deaths in that town among children, within the first three months, was one in 9.57 births; which is intermediate between the mortality in the northern and southern departments of France, as given above. Of 532 deaths among children of the same age, 163 occurred in the months of December, January, and February,-113 in April, March, and May,-125 in September, October, and November,and 131 in June, July, and August. On taking the proportion of deaths to births, the average, for the winter quarter, is one in 8.43 births; for the spring quarter, one in 12.05; for the autumn quarter, one in 10.65; and for the summer quarter, one in 8.95.—Ibid.

4. Nature of the Urine, during the formation of the Cystic Oxide Calculus. (Journal of Science, Literature, and Arts, January to March, 1830.) Dr. Venables of Chelmsford, has lately had a good opportunity of carefully examining the urine, in a case of that rare form of calculus in the bladder,-the cystic oxide. The only instance where the urine had been previously examined in the same circumstance, was in the case of a gentleman mentioned by Dr. Prout, in his work on the Diseases of the Urinary Organs, (p. 166,) who found that the urine varied in density from 1020 to 1022, was rather abundant, faintly acid, of a yellowish-green color, and peculiar odor, that there was formed, on standing, a greasy-like film on the surface, and a copious pale precipitate, both of which were composed of triple phosphate of ammonia, and magnesia, and cystic oxide, that cystic oxide was also precipitated on the addition of