Chapter XVI: Letter XIX: gives a definition of the ellipsis, which would be a (10)

In the second place, we may, I think, affirm with tolerable certainty, that no nation ever contained so many large cities. On this point Great Britain exhibits a splendid superiority. We have two cities of the first class, London and Dublin; the one with a population of more than a million, the other with little less than three hundred thousand. Of cities of the second class, or those which reach one hundred thousand inhabitants, [p285] or above that number, we have seven, _viz._, four in England, Manchester, Liverpool, Birmingham, Bristol; two in Scotland, Edinburgh and Glasgow; and one in Ireland, the city of Cork. These seven average considerably more than one hundred thousand each. We have fourteen towns of the third class, or those containing from thirty to fifty thousand or upwards of inhabitants, _viz._, ten in England: Portsmouth, Plymouth, Norwich, Leeds, Sheffield, Nottingham, Bath, Newcastle, Coventry, and Hull. Two in Scotland, Paisley and Dundee, and two in Ireland, Belfast and Limerick. Of towns of the fourth class, in which are usually reckoned those of from fifteen to thirty thousand inhabitants, we have at least thirty, and probably more. A slight glance at the principal nations of Europe, with this view, will show at once their immense inferiority.

To begin with France, the most populous of the great sovereignties. That empire possesses only one city of the first class, _viz._ Paris, which is inferior to London by one third. She has five of the second class, _viz._, Lyons, Bourdeaux, Marseilles, Lisle and Rouen; but, according to the latest information which I have been able to obtain, they will not reach, by a very considerable proportion, the average number of the seven English cities of the same class. France has also eight towns of the third class, _viz._, Amiens, Caen, Nantes, Brest, Toulouse, Toulon, Mentz, and Versailles. I am not quite sure, as no census has lately been taken, whether two or three of the following towns ought not to be included in this class, though I am inclined, on the whole, to a contrary opinion, _viz._, Melun, Montpelier, Nanci, Dijon, Tours, Rennes, and Troyes; they will not, however, I am persuaded, come near the average of the British third-rate towns. The same remark will hold as to the number and size of the inferior towns.

With respect to the rest in rank of the great monarchies, the Austrian Empire, a very few words will suffice, as it cannot pretend to come into any competition with us, on the point in question. Austria possesses only one city of the first class, and three of the second, _viz._, Vienna, Prague, Milan, Venice. The towns of the third rank are proportionably few. With Spain, Russia, and Prussia, it would be idle to enter into any comparison. [p286]

It must be confessed, however, that the present kingdom of the Netherlands, as established by the congress of Vienna contains, in proportion to its extent and population, more large towns than any single state which now exists, or perhaps has ever existed. With an extent of territory and number of inhabitants scarcely exceeding, one-fourth of the British dominions, that kingdom has one city the first class, Amsterdam; two of the second rank, Rotterdam and Brussels; and probably as many of the third class as Great Britain herself. But the Kingdom of the Netherlands is in itself too insignificant to enter into any competition with such a state as Great Britain for any objects of general comparison. The various states comprehended under the common geographical appellation of Italy, if that superb country was united under one head, is the only one of the European nations which, under the view we are now considering, could sustain any parallel with Great Britain. But this union, so desirable in many points of view, would probably diminish its pretensions as a nation of large cities. Many of these have reached their present grandeur and extent by having been long the seat of a court or a government, and would perhaps decline considerably if reduced to the rank of mean provincial capitals. But even under any circumstances of territorial union, Italy could not be held to comprize more than one city of the first class, _viz._, Naples, and six of the second, _viz._, Turin, Milan, Venice, Genoa, Florence, and Rome; whereas, as we have just seen, Britain has two of the first and seven of the second, and these superior in size and number of inhabitants.

The third peculiarity which I have to remark in the actual situation of the British dominions is, that no nation ever had so great an _urban_ population, or so large a proportion of its inhabitants residing in towns. This peculiarity is intimately connected with that which I have just described; but it is nevertheless a very different characteristic. Great Britain is not only distinguished for the number and size of her large cities, but for having so _great_ a number of them on so _small_ a territory. By the census of 1811, it was found that nearly half our population resided in towns, and at present, I apprehend, the proportion will be found still greater. In this [p287] respect no nation has ever approached us. The French economists were of opinion that not more than one-fourth of the people of France lived in towns; and the later statists, who have alluded to the subject, contend that a still greater proportion of the population is rural. This will not appear exaggerated when it is recollected that all the lower classes of that country subsist principally on vegetable food, and that, consequently, the greater part of the soil being under tillage, a great number of hands is required for its cultivation. In Great Britain, on the other hand, the inhabitants of all classes consume a great quantity of animal food, and, of course, a great part of our lands, being in a pastoral state, require a small proportion of occupants. In the kingdom of the Netherlands, it is supposed about one-third of the inhabitants live in towns: in Italy about one-fifth: in Austria, Spain, and Russia, except the province of Siberia, where the abundance of manufactures congregates the people in masses, not more than one-fifth. In Russia, Sweden, and Norway, where, amongst the lower classes, nearly every family is its own manufacturer, not more than one-eighth or one-ninth.

The fourth and last of these peculiar characteristics which I shall remark, is, that no great nation ever employed so large a proportion of its people in trade and manufactures. In speaking thus, I leave out of the question the Italian and Flemish republics of the middle ages, and the Hanse Towns, free cities, and United Provinces of later times. I speak only of great and extensive countries. It will appear, I doubt not, by the present census, that at least half our whole population is employed in trade, commerce, or manufactures. This is a feature altogether singular; a circumstance to which no parallel can be found in the ancient or modern world.

From these premises, a few observations, in the way of corollaries, will naturally suggest themselves.

In the first place, such a state of things is indicative of great wealth and power. A country thus situated is, beyond any other, powerful for attack and strong for defence. A profusion of great cities can only be produced by extensive trade, and can only be maintained by a highly cultivated soil. The wealth acquired by the industry of the towns, reacts on the [p288] industry of the agriculturist, and it is in this that the real advantages of commerce primarily consist. In this way an extensive population is gradually generated, for no maxim or political economy is now more generally admitted, than that population is sure to follow close and to press hard against the means of subsistence. An affluence of inhabitants on a comparatively small territory, is, itself the primary ingredient of power, and this first requisite of strength is, in the case of Great Britain, essentially corroborated by our insular situation. Surrounded by dangerous coasts and tempestuous seas, we can only be approached at certain points and certain times; whilst, on the other hand, as this state of things supposes and supports a powerful navy, we are able in a great degree to choose our point of attack.

From a population such as we have described, of which only a very limited part is employed in creating the means of actual subsistence, a very considerable portion may always be abstracted for purposes of attack or defence. It is usually calculated, that one-fifth part of the inhabitants of every country is capable of bearing arms. On this calculation, Great Britain contains four millions of fighting men, of whom it is believed one million might be formed into an army without any very serious interruption to the essential operations of agriculture and commerce. This supposition may seem a little extravagant, but it must be recollected that, at one period during the late war, the number of men under arms was actually calculated at seven hundred and fifty thousand.

In the second place, such a state of things is favourable to public liberty. The congregation of men in great masses is found to give great force to the influence of public opinion; by the spirit of discussion which it generates; by the anxiety for intelligence which it diffuses; by the collisions of opinion which it engenders, and by the facility of union which it affords. Nations purely or principally agricultural are generally under a despotic government, especially large states, for the maxim of _divide et impera_ is applicable as well to internal as to external politics. Ancient Persia and Assyria, and modern Russia and Poland, are instances in point. The fierce and demoralizing tyranny of the feudal system, which, after [p289] the destruction of the Roman monarchy, left scarcely any other division of the people than those of tyrant and vassal, could only be effectually broken by the rise of great towns. These communities were alone competent to resist the aristocratical and subordinate despotisms into which all the nations of Europe were subdivided, and which, as is well known, overawed the throne, whilst they enslaved the people. In confirmation of this, it may be remarked, that the free republics of antiquity, as well as those of the middle ages, derived the spirit which nurtured them almost entirely from the capital city; and though, in the former case, there was scarcely any commerce to excite the activity of the people, yet the mere congregation of a numerous body of men sustained the power of public opinion.

But the most important question remains behind. Is a civil community thus constituted favourable to individual virtue and happiness? This is assuredly the point which it most behoves us to ascertain, since no truism is more obvious than that power and opulence, and refinement and splendour, and even liberty itself, are only so far valuable as they tend to make men wiser, and better, and happier. Is it true, then, that Great Britain has anteceded other nations in these fundamental points, as much as in those we have just described? This question cannot be answered without some hesitation: for we may say, with Addison’s facetious Knight, “that a great deal may be urged on both sides.” On the one hand it is certain that our situation is eminently favourable to intellectual improvement. The increasing spread of instruction, and the rapid advancement of knowledge which are necessarily concurrent with our career of prosperity, must ultimately advance us in the scale of moral and rational agents. If knowledge be power, it is also happiness; for communities as well as individuals would all be happy if they knew how to be so. It is also certain that the incessant struggles of competition and the strenuous efforts for distinction which are always at work in an over-peopled and highly refined country are favourable to the active virtues. They operate amongst the higher classes to provide many objects of laudable ambition; and amongst the lower, afford perpetual facilities for bettering their condition, [p290] and furnish an incessant supply of occupation, the want of which is sure to open the door to the incursion of all the worst propensities and basest vices. They bring into action all the resources of human ingenuity; all the aids of fortitude and enterprise; all the trials of patience and perseverance; all the equanimity demanded by the constant mutations and rotations of fortune. It is not to be denied, moreover, that the first-rate virtues of beneficence, charity, and hospitality, take root and flourish with peculiar vigour in a commercial community. The fluctuations of condition to which almost every man knows himself liable, and the constant proximity of distress and opulence, offer perpetual excitements to the benevolent affections.

These, it must be confessed, are important ingredients in the composition of human happiness; but considerations not less momentous present themselves on the opposite side, for every thing in human affairs is on a system of compensations. It is not to be denied that a state of society, in which one-half of the population is congregated in towns, and nearly a moiety of this half crowded together in enormous factories, is highly unpropitious to virtue, to health, and to happiness. In these huge receptacles of human labour, it would be absurd to expect that the women should be distinguished for their modesty and propriety, or the men for their prudence, temperance, and regularity. It is an unhappy law of human nature, that the force of example is most prevalent on the side of vice. A few depraved characters scattered amongst a multitude are commonly found sufficient to corrupt the whole mass: hence we may always expect to find, in the seat of a great manufactory, all the worst ingredients of civilized society; all the base depravities of a luxurious and opulent community, combined with much of the grossness and rudeness of the savage state: in a word, all the corruptions of high civilization without any of its polish. Nor is this mode of life, generally speaking, more favourable to health and comfort than to good morals. The constitution of the young is impaired, and their growth retarded by excessive labour and close confinement. Those of maturer age are glad to seek relief from the depressing effects of a wearisome and monotonous labour, unwholesome air, and constant [p291] restraint, in intemperate indulgence; and all the long train of vices and miseries to which the poor are liable, follows of course. Nor are their prospects for the future often such as to encourage hope or stimulate exertion. The habitual improvidence of the poor is aggravated in their case by the dangerous fluctuation of their trade. Sometimes they are eagerly courted with high wages, and lavish promises; at others, no employment is to be had, and not enough can be earned, even by the most unnatural exertions, to sustain their families. Nothing can be imagined more fatal to order, regularity, and comfort, than these vicissitudes. Hence it commonly happens, that, in the decline of life, these poor creatures are driven to the sad resource of parish relief. It is moreover not one of the least evils of the manufacturing system, that it has a tendency, in prosperous times, to generate an excessive population, which, on any great reverse, is suddenly thrown on the community as a superfluous burden. The changes of a fashion, the caprice of public taste, or the sudden interruption of a foreign market, will reduce thousands to helpless and unexpected poverty.

It must, however, be admitted, that the picture of rural life has also its unfavourable aspect. Those who retire into the country are apt to find themselves somewhat disappointed in their expectations of rustic simplicity and pastoral innocence. In situations where every breath of air, and every feature of nature express nothing but peace and love, they are a little surprised to see the selfish and malignant passions at work in all their baneful activity; to find, as in the purlieus of a court, the symptoms of “envy, hatred, malice, and all uncharitableness.” Still we shall find that instances of utter depravity and abandoned profligacy are of much rarer occurrence than in great towns. In a village, every individual is known, and the very consciousness of being conspicuous, creates a sense of shame which is highly salutary. It has often been observed, that men in a body will commit, and even justify, atrocities which no individual amongst them would be capable of attempting, if not screened by the shelter of a crowd. We find, accordingly, in the annals of Wesley and Whitfield, that the great scenes of their operations are in collieries, factories, [p292] mines, canals, and all the other appendages of a great commercial and manufacturing nation. It was there, according to Whitfield, that the “Arch Enemy” raised his triumphant standard; it was there, that the harvest of lost souls was ripe and abundant. But the most decisive proof of the comparative purity of the rural population above that of the manufacturing districts, is the fact that the single town of Manchester will furnish ten times more criminal prosecutions than two Welch counties which contain an equal number of inhabitants.

On the whole, I think we cannot escape the conclusion, that, though a certain degree of commercial and manufacturing property is necessary to stimulate the agriculture of a nation, and to call forth its utmost powers of production, yet that it is not desirable that this country should proceed much further in that dangerous career, or increase still further the disproportion between its urban and rural population. The late increase in our numbers is so rapid and alarming, that I am afraid some positive checks (to use Mr. Malthus’s language) of very terrible potency must soon be brought into action. The forcible lines of Goldsmith, though that great poet knew little enough of political economy, are applicable to the wise and benovolent statesmen of all times—

’Tis theirs to judge, how wide the limits stand
Between a splendid and a happy land.

_On the Modern Ornaments of Architecture, &c._

In no age since the Augustan era of Rome, perhaps, has decoration of the interior of dwellings been carried to greater excess than at present; nor, since the days of the florid style of Gothic architecture, has the exterior received more embellishment. Architectural ornaments have generally been copied from the antique, those especially which belong to the orders. Indeed there is a kind of classical standard, which governs the architect in the execution of public edifices, from which he cannot with propriety depart. National, and regal emblems, wherever suitable, should always be introduced in public buildings, and in those of a private or mixed character [p293] all legitimate ornaments may be displayed. Of this class the acanthus, vignette, the branches of the olive, and leaves of the palm, the crown of laurel, the chaplet of myrtle, and the wreath of roses, are all proper when judiciously introduced; and the rose and honeysuckle flowers, and the folicles, trefoils, cinquefoils, &c., which so often occur on sculpture and plaster work, are also proper, because they are imitations of nature.

But in our present style of decorative execution, from the most elaborate finishing of a regal palace, down to the pattern of a milk-maid’s gown, there is such latitude taken in the display of licentious fancy, that imagination itself is baffled to find anything in the infinite variety of nature’s works, to which their designs can be compared, or to which they bear the most distant resemblance!

It is really unaccountable, that the whole tribe of our artists, the ornamental statuary, scagliolist, paper-stainer, weaver, chintz and cotton printer, &c. should all be “straining their low thought to form unreal” forms and figures; and striking out the most intricate and complicated, to the utter neglect (except in very few instances) of those numberless simple though transcendently beautiful configurations, which everywhere appear in the works of nature.

This is surely a dereliction of all propriety, an exuberance of grovelling taste which no consideration can excuse, nor reason justify. In this age of refinement, good taste should be the guide in all things where invention is necessary, and design requisite; whatever is grotesque or fantastic, should be banished from our labours of art, and the elegant forms of vegetable or animal nature alone take their place.

If it be asked, how it happens that such obliquity of fancy (for it cannot be called taste) should so generally prevail, the answer is, were these pattern-mongers to copy from nature every body could judge of their ability as imitators, and, if unfaithful, would decry the artist; whereas, whilst bringing forth his nondescript and nondescribable forms of imaginary figures, he escapes the lash of the critic, which otherwise he would be subjected to. [p294]

It may be granted, that it is as ridiculous to form stone or plaster flowers, as those geometrical frets and fanciful nothings which are usually pourtrayed in architectural decoration: but it may be answered that if any ornament be necessary, that of a nondescript character is not more appropriate, as such, than natural forms would be; and these latter having a name, and many of them an emblematical character, may be often applied with a propriety which cannot belong to the other.

The old fashioned tapestry, notwithstanding its sombre appearance, was in its plan much more rational than the multifigurations of our modern paper hangings. The first represented some historical event or legendary tale, yielding some mental information, or it taught perhaps a moral lesson—the eye was amused while tracing the ideas of the ingenious sempstress; but in our ephemeral and gaudy ten-thousand-times repeated _paper_ nothings, there is no design to interest, nor combination to amuse the eye longer than a transient glance. Even the Chinese, who, in all their decorative finishings shew _rigidity_ itself, have escaped from tame mannerism in paper hangings, by imitating, from the edge of the carpet to the ceiling, all the gradations of turf, herbs, shrubs, and trees, upon a sky ground, enriched with figures or rather portraits of flowers and fruit, as well as beasts, birds and insects. This though it cannot deceive the spectator for one moment in mistaking a fictitious for a real scene, yet is certainly far superior to European paper-upholstery, as it at least may introduce a knowledge of natural history, which the latter has no pretension to, indeed seems studiously to discard, as beneath imitation.

All this vitiated taste, or fashion rather, is to be regretted; especially as it appears that those

Fancied forms which on the ceilings sprawl, And shapeless frets which decorate the wall,

are just as expensive, and difficult of execution, as the most elegant imitation of vegetable or animal configuration would be; and surely when such variety of forms are presented to the artist, they deserve to be copied as transcendently superior to the capricious fancies of the most celebrated decorator, or of [p295] the most splendid fashionable designs; either in the works of the sculptor, scagliolist, &c. or the more insignificant designers of figured paper or drapery. Indeed there can be no good reason why ox-heads and garlands (now the days of sacrifices are past) should not be banished from the frieze and entablature, to admit the far more appropriate figures of foliage, fruit, and flowers, aquatic as well as terrestrial, which every garden yields;—and for interior enrichments of cornices, mouldings, &c., the curious and elegant forms of the testacea, would afford beautiful copies for imitation.

In fine, if there be any merit or propriety in the adaptation of whatever is elegant in form, beautiful in outline, harmonious in tint and proportion, and congruous in combination, such may readily be found in the animal and vegetable kingdoms. Faithful representations of such objects, not only open a fine field for the exercise of individual ability, at this time, but also a source from which might be drawn a large share of public patronage, and consequent commensurate reward. Indeed it is now pretty evident that in many things, especially in the minor works of art, we have been too long and too rigidly impressed with a veneration for the works of antiquity, or what is equally benumbing, a passive following of tyrant fashion; and that many a bright genius has been “nipped in the bud,” and remained “twinkling in the socket” of Grecian and Roman rules, who, if venturous enough to have burst the shackles of professional thraldom, would have improved and elevated his art, as well as himself, by designs and works which would have advanced his profession and adorned his country.

But it is not yet too late; a knowledge and study of the genuine elements of taste, whether of art or nature, and a mind embued with rational perceptions of all that is beautiful and picturesque, and grand or sublime in either, will rise superior to all precedential fetters, as well as all modern mannerism, and will equally regard the excellencies of the ancients, as it will avoid the errors of some modern artists, who, in leaving the beaten track, have deviated far and widely from the point to which good sense and good taste would have led. [p296]

A list of plants, &c. which exemplify all that is elegant in form, beautiful in outline and graceful in position, should have accompanied the above imperfect remarks, but this must be deferred to another opportunity.

J. M.

_De l’Influence des Agens Physiques sur la Vie. Par_ W. F. Edwards, D. M., &c.

[Continued from the last Number.]

In our last number we presented our readers with a general abstract of the first part of this valuable work. The second part refers to animals of the _cold blood_ order, including _fish_ and _reptiles_. The _larvæ_ of the latter underwent some comparative experiments detailed in the first chapter, because they partake of the nature both of _fish_ and _reptiles_, as to their _respiratory function_; the imperfection of their intermediate state and developement of organization not interfering with the objects in view, and the double mode of aërification being exercised unequally. The _skin_ of these young animals furnishes them with the means of producing the requisite changes in the blood by _absorption_, as in the adult, while it lives in water; and the cutaneous respiration goes on through this medium at a temperature which the subsequent more perfect animal is unable to endure. The object entertained is the influence of physical agents upon the changes which these animals pass through in their form and structure.

An important condition of their advancement to maturity seems to be, that the nutriment suspended in the water should be in very small and limited proportions. Temperature also influences their constitutional changes.

Sometimes the _larvæ_ pass through the winter in their primitive state; a fact not generally known. Some _tadpoles_ were confined within wooden boxes submersed in the river Seine, in which holes were perforated to allow the stream to pass through, without the possibility of the animals rising to the surface of the water, and thus to inhale air. Others were placed in a large vessel of Seine water renewed at intervals, with power to rise above the surface. Ten in twelve of the first box underwent no transformation, the others having gone partially through their change. But [p297] those of the large vessel, and not submersed in the river, passed through their changes of form without the least appearance of the phenomenon being retarded. The running waters of the Seine probably contained nutritious matter, which the water periodically renewed was more deficient in.

Under circumstances of moderate nourishment and temperature, the tadpoles under water did not complete their changes but in a very partial and protracted manner, while the greater portion made no change. The great difference in the circumstances of the experiments seems to have been the access to the air of those which went through their transformations as usual. Exclusion from light made no difference in the results, and these were solely influenced by occasional renewal of air from pulmonary respiration.

These animals possessing a double respiration, cutaneous and pulmonic, that is, absorbing air from the water around them and inhaling it from the atmosphere on its surface, renders these facts highly curious. Fish possess only the means of aquatic respiration, and the influence of temperature was tried upon them submersed in water deprived of its air by previous boiling, the heat being varied from 0° to 40°. The fish died quicker under these circumstances than the frog species in the same situation; but their lives were prolonged more in the _descent_ of the thermometer than during its _elevation_, as also occurred with the experiments on frogs and salamanders; and, in both cases, the younger the animal, the less it could resist the higher temperatures. At 40° the young animals only survived about two minutes, and the adults many more.

Fish were also submersed in closed vessels of aërated water, and, by varying the temperature and the quantities of water, the duration of their lives was augmented in proportion to the increased volume of the liquid, the temperature remaining the same; but when these experiments were conducted in open vessels, the contact with the atmosphere altered the phenomena. At 20°, a small fish expired in four hours; and when the temperature was lowered to 10° or 12°, the same sort of animal lived several days; and when the water was kept clean by being changed every twenty-four hours, the fish lived indefinitely.

It is known that fish rise periodically to the surface of the waters to respire; and Dr. Edwards discovered that they did so when they have reduced the properties of the air [p298] dissolved in the water to a lower standard than is requisite for the proper aërification of their blood; thus renewing their supply of _oxygen_.

The functions of this class of animals have always been obscure; and their phenomena are different from those of others. Different species of fish die at various periods when deprived of water, some in a few minutes, others in a few hours; and it appears that their dissolution arises not so much from incapability of atmospheric respiration (for the experiments of Sylvester prove that they can respire pure air), as from the different state of the air.

Some experiments on _lizards_, _snakes_, and _turtles_ conclude the researches among cold-blooded animals. The skins of these, like those of the frogs and salamanders, received vivifying influence from the air, mainly acting, in conjunction with pulmonary respiration, to promote their existence. _Snakes_ and _turtle_, their pulmonary respiration being insulated, from their skins being guarded from atmospheric influence, were found alive; but the _lizards_ died in a few hours, when the vivifying contact of the air was removed from their bodies, and they breathed only by their mouths. Animals naturally defended by _scales_ transpire much less than such as have their skins free. Thus _frogs_, _toads_, and _salamanders_ yielded more by perspiration than _lizards_, _snakes_, and _turtle_, in a given time; and the porosity of the skin of course regulates the facility of transpiration in all cases.

With these experiments and remarks, Dr. Edwards concludes the second part of his researches. The third part includes _animals of warm blood_, in which will be found some curious and interesting remarks on the heat of young animals compared with that of adults.

Dr. Edwards refutes the common notion of young animals being necessarily hotter than adults. The heat of young puppies was very near that of the parent, or one or two degrees less, but this variation was not constant. Some new-born kittens and rabbits were also subjected to similar trials, and the results led to a conclusion that the temperature of young animals is _less_ than that of adults.

According to these experiments, the power of resisting the cooling influence of the air acquires force as the animal grows up; and those examples related, in which artificial covering was adopted, show that nudity is not the only cause of the reduction of heat, which is, in fact, more referrible [p299] to their infantile constitution. At first the sucking animal shows little variation from the parent temperature; then this becomes more and more reduced, and about the fifteenth day it is a degree or two below the mother.

Birds, which are warmer than mammiferæ, were next made the objects of experimental inquiry, and the young recently hatched exhibited a _lower_ temperature than the grown birds. After removal from the shelter of their nests into a mild atmosphere of 17°, in one hour they cooled down from 36° to 19°, thus losing 17° in an hour. At an elevation of 22° the same results were obtained, and they cooled down to within one degree of the surrounding air. The plumage of birds has little if any influence upon their temperature. The production of heat lies within, and not on the surface of the animal; and if it be strongly developed, the removal of natural coverings does not influence the heat produced; and if it be weak, their addition will not prevent cooling. Birds recently escaped from the shell cooled to within two degrees of the air, whereas the unplumed adult birds scarcely lost one degree.

The distinctive character of warm-blooded animals to preserve an uniformity of heat has no reference to _bulk_. The _eagle_ maintains the same temperature as the _wren_ or the _tom-tit_, taking them at the same age, and placing them under the same circumstances; but if cooling measures be adopted, the lesser body parts with its heat faster than the larger, though ultimately they arrive at the same point. The dimensions of animals are infinitely varied; but the giant reaches no higher standard than the dwarf, nor sinks to a lower temperature.

In estimating the temperature of young animals, it must be taken into account that they are born at different periods of organic developement. Some come earlier into the world than others, and some are more perfectly formed than others at their birth, and more capable of helping themselves. This variation produces a different standard of heat after birth, and especially creates a variety of temperature among birds when tested at the same epochs of their existence. The season in which animals are produced also modifies their temperature.

The influence of age in modifying temperature is common both to mammiferæ and birds. Young and healthy sucking pigs cooled faster than their parent, their generating means of heat being more feeble. Animals of warm blood possess [p300] the power of supplying heat at its _maximum_ when first born; they then part with it by degrees, and, as they advance in age, their heat becomes gradually augmented again till it reaches the adult standard.

Dr. Edwards next proceeds to discuss the phenomena of animal temperature more exclusively regarding adults, and especially among those singular creatures of the mammiferæ which form an exception to the general law of nature respecting the uniformity of temperature as to warm-blooded animals. These beings are what are termed _hybernants_, such as the _dormouse_, the _hedgehog_, the _bat_, the _marmot_, &c., natives of Europe; which remain dormant during winter without any external signs of life and motion. The change which these undergo reduces them from the state of warm-blooded animals to that of cold. Unlike the rest of their class, the autumnal season lowers their temperature by degrees, till in winter it reaches so low as to be scarcely higher than the surrounding air. Their powers fail gradually, and their losses of heat are not repaired, till at length their respirations become slow and feeble, and the heart languidly urges the blood through the arteries. In this state there is an imperfect aërification of the blood, and a partial state of asphyxia, producing continued repose of the nervous and muscular system. But the temperature of these animals sinks no lower than the air, and remains sufficient to maintain a passive existence, till the returning spring raises their heat again, and they become lively and active till autumn; but even in spring these animals are characterised by producing less heat than others of their class.

If we seek to know the cause of this curious variety, we can only refer it to peculiarity of constitution, which is instituted by nature as adapted to animals placed in situations of rigorous cold, and where they cannot procure sustenance but in spring and summer.

Our author imitated the process of hybernation by artificial cold, and produced the same effects; and when he restored animation by gradual warmth, he found the animals as lively as before.

John Hunter and others have written on the natural history of hybernants, and Dr. Edwards regards only their temperature. The experiments on hybernants by artificial cold prove this fact, that hybernation is attributable to other causes than to the reduction and deprivation of nutriment; for the animals submitted to the ordeal of cold were well [p301] fed, and in the lively season of advanced spring. The deprivation of food seems to be a local consequence provided for by the phenomenon of hybernation, and not its exciting cause. Nor does there appear to be any change of organization in these cases, but a state of constitution exists which we are unable to account for further.

We have, in the next place, a series of experiments showing the influence of the _seasons_ upon animal temperature with the warm-blooded; by which it seems that they produce a variety of results: and it is demonstrated that animals of warm blood in general undergo some constitutional changes with the periodical returns of the seasons. When, for example, the highest degree of temperature is attained, animals no longer produce heat; so that their temperature continues below that of the air in the hot season. And, in the cold season, if the cold be not too rigorous, the animal’s age offers a proportionate resistance to the cooling effects of the air as the approach to maturity is attained. An elevated and a depressed temperature thus produce contrary effects upon the internal powers of generating animal heat, a high temperature arresting them, and a low one promoting them. _Thus we cannot fail to observe the beautiful adaptation of means to final causes_.

Upon the subject of _asphyxia_ in warm-blooded animals, Dr. Edwards found a great dependence between animal heat and the faculty of living without contact with the air, a state in which the blood is not aërated by respiration, and which is sustained by hybernants while in the dormant condition. Having submersed animals in water of various temperatures successively, so as to bring them under the influence of variable temperature, he found the _descending_ scale of temperature the most hurtful. The _ascending_ heat was that which prolonged life most. Between 20° and 10° the results were similar to those between 20° and 40°.

Animals, then, of warm blood in a state of asphyxia hold their existence on two principal conditions relative to heat; one regarding the different measures by which some develope their heat, and the other the degree of external temperature. The first is proper to animals naturally, the second fortuitous.

Upon the _respiration_ of both young and adult animals the author arrives at a conclusion opposite to that of common opinion, which is founded on the notion of the heat in young animals being higher than that of the matured. Finding, [p302] however, as already noticed, that the parent exceeds the temperature of its offspring after birth, it is naturally concluded that its consumption of air is also greatest. This was experimentally confirmed, and is in unison with other facts. In the first part of this work the vertebratæ of cold blood were also found to consume least air in proportion to their diminution of temperature. Temperature seems to act uniformly with all the vertebratæ, and their consumption of air is in proportion. The _mammiferæ_ have a lower temperature than _birds_, and they consume less air than the latter. Fish and reptiles consume less air than the warm-blooded, and possess a lower temperature.

The influence of the _seasons_ upon _respiration_ is considered in the sixth chapter. Many changes occur in the atmosphere during the revolutions of the seasons, varieties in the temperature, and the pressure and density of the air. Dr. Edwards shows that the faculty of producing heat with warm-blooded animals is greater in _winter_ than in _summer_, the constitution of animals being adapted to their individual climates; and in reference to the relation of this faculty to the consumption of air, it is presumable, all other circumstances being alike, that the consumption ought to be increased with the faculty of developing heat, and the experiments justify the presumption.

Upon the subject of _transpiration_, it is shown that the air not only exercises a vivifying effect upon the constitution, but one little less important in removing a vaporous substance from the surface of the body, and which is separated from the fluids before its conversion into vapour, and known by the name of perspiration or sweat, which transpires from the skin. The variations in the temperature of the air possess great influence over this function. Experiments on this subject were detailed most fully in our last Number, relative to cold-blooded animals; and therefore these need not now be repeated in respect to the warm-blooded, for the results are exactly similar, as to transpiration in equal and successive periods, the comparative influence of dry and moist states of the air, and the effects of air in motion and in repose. Inspection of the table annexed to the work displays the similarity of the effects produced by the same physical agents upon cold and warm blooded animals, and this accordance serves to afford mutual support to the different investigations.

We are now arrived at the fourth and last part of this [p303] work. Much, however, of this part appertains to what has been already detailed upon other animals. But the modifications of heat in the human being, from the period of birth to maturity, will be found highly interesting. They accord precisely with the results obtained among the lower animals and mammiferæ; and present analogical proofs of the general application of principles laid down in the preceding portions of our notices.

While, however, we trace analogy throughout the animal kingdom, it must be remembered that there are infinite sources of variation arising from the extensive variety of species modifying those principles, which are governed by a general harmony of effect. Of all animals, man exhibits this variety the most, possessing, as he does, attributes above all the groups of his class, from his intellectual properties, speech, &c., rendering his race unique and superior to all others. Our curiosity cannot, therefore, be allowed to rest satisfied with the general application of principles, until we have observed their modifications in the human being as well as in brutes. It is highly interesting to inquire into the conditions of human phenomena, and examine the forces which man opposes in his intelligent character to the physical agents around him. He is equally liable to their influence, exists by their contact, and yields, like other members of the animal kingdom, to their destructive tendency. The essential distinctions appertaining to his economy are thus the more necessary to be understood. His _organization_ affords him no shelter from the operations of physical laws beyond that of brutes; but the superiority of his nature may be supposed to modify their influence from causes referrible to his _sensibility_. These have formed the subject of Dr. Edwards’s inquiry.

Man’s state and condition, at his birth, place him in very different circumstances from those at which he subsequently arrives. Here, therefore, we see an extensive field of inquiry; and it is suggested whether, in the infantile state, man generates _less heat_ than in more matured existence. Dr. Edwards has shown that the young of mammiferæ generally, being born at the period when their eyes are open, produce _less_ heat than adults. It is, therefore, presumable that the generating powers of heat differ in the two states of existence which man goes through, the infantile and mature.

But the power of producing heat differs among adult animals, and it is desirable to know the limits of this faculty, [p304] Moreover, this power differs in different parts of the body; so that, when experiments are made, we should always apply the thermometer to the same part of the body. Among twenty adult persons, Dr. Edwards found the average temperature 36°.12: in infants from a few hours to two days old, 34°.75 was the average. Thus we perceive that the temperature of human infants is _inferior_ to that of adults. In infants born previous to the usual period, two or three hours after birth their heat was at 32° of Reaumur’s scale. So far we perceive a similarity in man to the mammiferæ in general.

We have next a chapter on the effects of _cold_ upon mortality at different ages. It is highly interesting to observe the care of animals towards their offspring, in protecting them against the effects of cold instinctively at a period before their own powers of generating heat enable them to resist its baneful tendency.

Dr. Edwards endeavours to investigate the subject of cold, so as to discover its limit of action. He examined the young of mammiferæ and birds, the former born with closed eyes, and the latter unfledged. He exposed them separately and apart to the air, so as to be independent of each other’s warmth, and they exhibited a temperature below their natural standard at the period of birth, even when a degree of artificial heat was applied beyond that of adult birds. The final result of these experiments was, that the application of heat may be conducive to their developement, but is not indispensable to their preservation. The author discovered, that the diminution of temperature is not equally injurious at all ages. The _younger_ the animal, the _less_ is the injury sustained by cold, because the faculty of producing heat is less powerful with the young than with the matured animal, the power increasing as the animal grows, and also with the increase of cold.

Still, however, this subject is open to inquiry, for the great variety of species, and other circumstances belonging to the animal creation, so modify the phenomena as to create an almost endless field of investigation. When warm-blooded animals are exposed by their parents to the atmospheric influence at an early age, they are better provided against the perils of cold, being born with an abundant source of heat. But, if the cold exceeds their powers of generating heat, the mortality is so much readier. Hence arises the danger of animals being born in the winter season. [p305] Two circumstances are distinguishable, the refrigeration of the body, and the temperature it is capable of sustaining. The cooling is so much less injurious with the young. If two young animals of the same species be cooled down equally, the youngest suffers the least. But, in order to lower to the same number of degrees the temperature of bodies of different ages, the external heat should be lowered in proportion to the advancement of the animal towards maturity, in order to compensate for the difference which the modification of age produces.

While it is true that the younger animals suffer least from cold, it is, at the same time, to be considered that they cool down more rapidly. On this principle depends the mortality of our domestic fowls and other animals, the management of which requires so much observation and experience in order to rear them. In regions where the temperature is liable to great alterations in the course of the year, man and other vertebrated animals of warm blood are liable to suffer in their health; for, though _cold_ should produce the resistance derived from the necessary constitutional developement of heat, this increase of caloric, having its limits, often exposes the constitution to the effects of too great reduction of temperature, as is exemplified in the frozen regions of the North Pole, in Siberia, and in Russia.

The young of mammiferæ, in general, were found by Dr. Edwards to differ very materially in the duration of their lives, in a state of asphyxia, often being limited to from five to eleven minutes, according to their developement at birth, the most advanced in organization living the longest period. The author proved these facts by placing animals in a state of asphyxia under water; and it is remarkable that, in all his experiments, the _voluntary_ motions were always first destroyed, the _involuntary_ outliving them. With dogs, cats, and rabbits, sensibility existed only three or four minutes. A puppy showed _automatic_ signs of life nearly half an hour. The best divers appear to be able to remain under water from three to four minutes.

When animals are entirely deprived of aërial contact, it may be inquired, what are the principal functions exercised? When the air circulates through the lungs, it imparts to the blood a peculiar quality, by which its colour becomes changed. Deprived of this influence from the air, the blood acquires a dark colour, and the _nervous function_ is [p306] simultaneously affected. Among _reptiles_, Dr. Edwards found that life could be maintained by this dark blood; but it is questionable whether the circulation of venous or dark blood can promote life in animals of the warm-blooded kind. Temperature certainly modifies their capability of existence. Under 20°, they live longest; at 0°, their existence is shortest. The vitality of the nervous system seems to be thus directly influenced by temperature.

Of all the phenomena of animal life, those relative to the blood’s state in asphyxia are, perhaps, the most interesting and curious, from loss of consciousness, sensation, and voluntary motion attending its disoxygenated state. If, however, animals differ so materially under the influence of a deprivation of air, as to the duration of such existence, we may imagine a corresponding difference relative to their respirations modified by species, age, &c. Air, the _pabulum vitæ_, is not equally consumed by all, but in different proportions; at least, such is the presumption from the experiments upon animals of warm blood. The relative proportions of this difference are sought to be ascertained. Warm-blooded animals of equal size and age, at their liveliest period of age, were the objects of comparative inquiry. We must refer the reader to the table at the end of the work for the results. A marked difference is observable between the quantity of air consumed by the cold-blooded animals and that required for the support of the warm-blooded; and each has an organization appropriated to the individual distinctions. Thus the structure of the reptile and fish entails the lesser consumption of air, compared with that of the mammiferæ and birds. Fish consume least air, reptiles stand next, then the mammiferæ, and, lastly, birds consume most. The two last, however, very nearly approach each other; so do also the two first; and the distinction between the organization and the consumption of air is most strongly marked between the fish and reptiles on the one hand, and the mammiferæ and birds on the other, which, indeed, has caused their separation into two distinct groups, by the appellation of _cold_ and _warm blooded animals_,—a distinction which clearly separates the whole of the vertebrated animals into two groups, bearing different physiological characters in their relations to animal heat and respiration.

The mere temperature of the blood in each group is insufficient for our knowledge of their distinctive characters. We [p307] further find them characterised by a consumption of air in union with their heat, so as to unite these two functions, and thus render them dependent upon the same organs. Dr. Edwards has further shown, that from birth to maturity the production of heat goes on increasing with the consumption of air. And thus age (as well as the seasons) has been shown to be a modifier of animal heat; for, as the hot season advances, the consumption of air becomes diminished, and when the cold sets in, it increases; and this decrease and increase are accompanied by corresponding developements of heat.

In cases of fainting, of hysteric and asthmatic fits, the principle here laid down, as to the balance between the air consumed and heat, is instinctively acted upon by the most ignorant persons, who open all the doors and windows to admit cold air, and dash cold water in the patient’s face. The addition or continuance of heat increases the affection. The application of cold produces instant relief. The state of asphyxia is relieved, the senses return, the pulse beats at the wrist, and the respiration goes on naturally. The _cooling_ renders the air, unfit before, fitted for the purposes of life.

The effects of temperature upon the respiratory movements are indicated also in those constitutional changes which diminish the production of heat and the consumption of air. Organic affection of the heart or lungs may produce this change, which entails the necessity of a change of climate, or an alteration of temperature artificially, to restore the balance between the air and the animal heat.

A very elaborate and complete argument, and series of experiments, are devoted to the subject of _transpiration_, and the effect upon it of the influence derived from repose of the body and sleep, by the air’s motion or stillness, and by the pressure of the atmosphere.

We have, however, pursued the interesting points touched upon so far as to render it impossible to enter at present upon this portion of the work. The importance of the subject demands a fuller investigation and report than we have now room for; and we must, therefore, defer it to another opportunity. [p308]