The mean height of the barometer, corrected, for the year, was 29.742 inches, and reduced to the level of the sea, 29.892 inches; this very nearly approaches the usually-assumed barometric pressure at the sea-level, or 29-92 inches, the difference being only 18 in deficiency as respects the year. The pressure of dry air at the level of the sea, would be 29.581 inches. The pressure of vapour in the air during eleven months, was ·284 inch, and the vapour in a cubic foot of air 3.26 grains. The total fall of rain was 31.24 inches; the mean of five preceding years being 34-04, and of six years, including the present, 33.6 inches. The number of days on which rain fell was 180, giving an average of nearly 3 days per week; the greatest number of rainy days being in January, and the least in September. The greatest height of the barometer during the year was 30-503 inches, on the 28th December, or at the level of the sea it would have stood at 30.653 inches. It was remarkable that at this period, when the barometer was considerably above 30 inches, the atmosphere was generally obscured by thick fogs and by frequent drizzle, with the wind from the S. and SE. The lowest depression of the barometer was 28.736, on the 14th July, with a S. wind, accompanied with a fall of rain (61) upwards of half-an-inch in depth in twenty-four hours. The range of the barometer has there

fore been 1.897 inches.

The distribution of the temperature of the year has been somewhat irregular. The month of January was remarkably mild, the mean heat being 41°.5 or about 7° above that of the year 1850 (34°·3); and notwithstanding the wetness of the season, the first two months of the year were not unfavourable to health. The mean temperature of the first half of the year was 45°.3, of the second half, 49°•5, and the mean of the whole year, 47°4—a number considerably higher than could be anticipated from the latitude. It remains to be ascertained, by future observations, whether the excess of temperature over calculation is dependent on local causes. The mean temperature to the west of the city, during the year 1850, was found by Mr James King, at 9 a.m., 47°-6, and at 9 P.M., 47°.7; and by applying the Greenwich corrections, these numbers become a mean of 48°, affording a close approximation to the results of the present year. The instruments were compared with the Greenwich standard. The highest temperature attained during the summer was 82°4, on the 30th June, and during the two preceding days the maximum thermometer reached 80°6 and 81°·1,- —a rare circumstance in this latitude. The highest heat at Greenwich Observatory, at the same period, was 87°, with a westerly wind. The lowest temperature of the year was 25°-9, on the 3d December, making a difference in the extremes for the year of 56°.5. The connection of the temperature with the mortality, in the different months, will be best observed by constructing a table on the following plan:

Mortality and Temperature in Different Months in 1851.

Mean Temperature, 41.5 40.9 41.3 44-3 60-1 54-1 58-5 56-8 52.9 50.1 38-4 427

The effect of cold on the total mortality is sufficiently obvious in November and December, and particularly on the aged and consumptive subjects. There can be less hesitation in tracing the increased deaths, in some measure, to the depression of temperature, as no epidemic prevailed peculiarly in these months. The fall of the temperature from 45° to 28°, destroys, in London, from 300 to 500 lives. Hence we can readily understand how it may have happened, that a considerable portion of the 237 cases of excess of mortality in December over October, may have been due to the operation of this depressing influence during the cold month of November. The effect of temperature may probably appear more striking from a comparison of the various quarters of the year in a population of 360,138

The total mortality during the winter quarters of the year amounts, according to this table, to 5551, while that of the two milder quarters is 5107, shewing a difference in favour of the warmer portion of the year of 444-the total mortality during the year being 10,746. That this mortality was not greater during the last quarter, when the temperature remained protractedly depressed, was undoubtedly due, in some measure, to the improved condition of the poorer classes in regard to food-that most natural and powerful bulwark against the attacks of disease. Notwithstanding, however, the circumstance that it is possible to account for the excess of

of

mortality in one portion of the present year over another by natural causes, there is an excess of deaths in this city over most other towns, for which some other origin must be sought. The forbidding aspect of a large portion of the dwellings in the older parts of the town, engendering, as they do, an absence of due self-respect, followed by low and debasing habits in their inhabitants, is scarcely surpassed, in regard to extent, in any other British city. Unfortunately, the application of proper sanatory measures, by the formation new, well-ventilated streets and houses, instead of the condensed habitations at present existing, has been confined to the great Metropolis, and will be employed as another argument in favour of centralisation, unless our local authorities are speedily prepared to devise and apply the adequate remedy. Another desideratum among those classes most liable to disease, is a plentiful supply of the purest water which can be obtained for domestic use, free from sewerage: the connection between impurity of water and mortality, having been well illustrated in the condition of London. Again, it becomes a question of import to health, if the noble Clyde, with its sewerlike waters and impure exhalations, be not equally conveying, in its present state of pollution, wealth and malady to a teeming city.

And lastly, the fearful mortality from smallpox and other endemics, urgently demands that the Scottish population should be placed on an equality with that of England, by an extension to our kingdom of the Vaccination Act, as well as of the Registration Act, which, if committed to the excellent administration of the RegistrarGeneral of England, could be brought into operation, with the machinery at present in existence, with but a trifling addition to the expense of the country. Scotland would thus be removed from the unenviable position of being classed with Spain, Greece, Hungary, Turkey, and Ireland, as the only parts of the civilised States in Europe where authentic official registers are not kept.

NOTE.-The blanks in the preceding Tables are due to the circumstance that the new form of Mortality Bill was introduced only in April.

On Fossil Footprints. By ROBERT HARKNESS, Esq.
Communicated by the Author.

Since the commencement of the present century science has made such rapid advancement that it in a great measure possesses a new and a different character. Some of its branches have so far influenced the progress of society that our present position results almost entirely from their application to the common businesses of life; and others may be

said to have had their origin since the beginning of the nineteenth century. Amongst these there is none which has made more gigantic strides than geology, which seems to have burst from its swaddling bands, and hurried forward in its progress until it has become of Herculean proportions. This rapid progress which geology has made is in a measure owing to the circumstance, that this science consists in the application of facts, which other branches of science have furnished us with, to the form, structure, and contents of the planet which we inhabit. In the application of these several facts it became necessary, that, in order to any great progress being made, there should be subdivisions in geology as to lead to the application of two distinct sets of facts; one derived from what, in a restricted sense, has been termed physical science, and the other, information which natural history has given to us. To the former we are indebted for a knowlege of the conditions which have caused the different mineral deposits, and also the mode in which these are arranged, as well as other circumstances connected with their occurrence; and to the latter we owe what information we possess concerning the various races of animals which have at different periods been occupants of our earth, and which mark epochs of existences, and indicate the commencement and termination of the several geological formations. A knowledge of natural history is required before any advancement can be made in ascertaining the forms and structure of the multitudes of species which existed anterior to the present. order of things; and as these ancient types of organic beings are devoid, to a great extent, of such characters as are now used in discriminating existing species, it became necessary that other and more permanent characters should be adopted, by which to trace out the affinities of extinct forms; and, consequently, we have that branch of natural history called Palæontology devoted to the examination of the characters and nature of the fossil remains which are obtained from the stratified crust of the earth. The remains of extinct races of animals are found in different states of preservation. Of the lower tribes of organic beings, such as zoophytes and shells, the structure is such as to furnish us, even in a fossil state,

with many distinct characteristics of their original nature. Even the whole tribe of invertebrate animals have their external forms commonly so well preserved as to afford sufficient evidence of their relationship to existing types. The case is different with vertebrate forms, more particularly with such as are inhabitants of the land; for these, when we have any traces of them, from the rocks which generally furnish organic remains, are in such a state as to afford commonly only a fragment of a bone or a tooth, and yet from such fragments the paleontologist is able to fashion the original animal of which these formed one part, to place it in its natural habitat, to tell us whether it browsed on a luxuriant vegetation, or fed upon the herbivora which were its companions on the earth; whether, like the lion, it consumed its food in its lair, or, like the hyena, dragged it to some dusky cave, there to grind the bones of its victim at its leisure.

The existence of former races of animals does not depend solely upon the remains which their structure has left in the form of their bones, teeth, or other solid parts. We have sufficient evidence to shew, that forms, of which we have no particle left, have at various times been inhabitants of portions of our earth, leaving no other traces of their former existence save their footprints on the soil over which they traversed.

The description of these footprints, and the inferences which have been drawn from them, has given rise to a branch of paleontology called Ichnology, and to this branch we are indebted for many important additions to our geological knowledge. The Indian hunter, as he pursues that vocation to which he owes his existence, acquires information concerning the various kind of animals which are likely to become his spoil, from the impress which they have made during their progress from one place to another; and the ichnologist, by examining the different tracks which he finds on the several beds of sandstone, arrives at a knowledge of the animals which have formed these tracks, and also infers from them what were the circumstances and conditions required by these animals when they were tenants of the sandy shore, which at early periods margined the tremulous sea.