and active. Thus, reptiles have feeble lungs, but a considerable liver; and thus too in fishes, which have no lungs, in the ordinary sense of the word, the size of the liver is often enormous. On the other hand, insects have a very large and complicated system of air-tubes; but their liver is minute, and its functions are habitually sluggish. If, instead of comparing the different classes of animals, we compare the different stages through which the same animal passes, we shall find further confirmation of this wide and striking principle. For the law holds good even before birth; since in the unborn infant the lungs have scarcely any activity, but there is an immense liver, which is full of energy, and pours out bile in profusion. And so invariable is this relation, that in man, the liver is the first organ which is formed; it is preponderant during the whole period of foetal life; but it rapidly diminishes, when, after birth, the lungs come into play, and a new scheme of compensation is established in the system.

These facts, interesting to the philosophic physiologist, are of great moment in reference to the doctrines advocated in this chapter. Inasmuch as the liver and lungs are compensatory in the history of their organisation, it is highly probable that they are also compensatory in the functions they perform; and that what is left undone by one, will have to be accomplished by the other. The liver, therefore, fulfilling the duty, as chemistry teaches us, of decarbonizing the system by secreting a carbonized fluid, we should expect, even in the absence of any further evidence, that the lungs would be likewise decarbonizing; in other words, we should expect that if, from any cause, we are surcharged with carbon, our lungs must assist in remedying the evil. This brings us, by another road, to the conclusion that highly carbonized food has a tendency to tax the lungs; so that the connexion between a carbonized diet and the respiratory functions, instead of being, as some assert, a crude hypothesis, is an eminently scientific theory, and is corroborated not only by chemistry, but by the general scheme of the animal kingdom, and even by the observation of embryological phenomena. The views of Liebig, and of his followers, are indeed supported by so many analogies, and harmonize so well with other parts of our knowledge, that nothing but a perverse hatred of generalization, or an incapacity for dealing with large speculative truths, can explain the hostility directed against conclusions which have been gradually forcing themselves upon us since Lavoisier, seventy years ago, attempted to explain the respiratory functions by subjecting them to the laws of chemical combination.

In this, and previous notes (see in particular notes 30, 31, 35), I have considered the connexion between food, respiration, and animal heat, at a length which will

"The size of the liver and the quantity of the bile are not proportionate to the quantity of the food and frequency of eating; but inversely to the size and perfection of the lungs. The liver is proportionately larger in reptiles, which have lungs with large cells incapable of rapidly decarbonizing the blood." Good's Study of Medicine, 1829, vol. i. pp. 32, 33. See Cuvier, Règne Animal, vol. ii. p. 2, on "la petitesse des vaisseaux pulmonaires" of reptiles.

Carus's Comparative Anatomy, vol. ii. p. 230; Grant's Comp. Anat. pp. 385, 596; Rymer Jones's Animal Kingdom, p. 646.

• Indeed it has been supposed by M. Gaede that the "vaisseaux biliaires" of some insects were not "sécréteurs;" but this opinion appears to be erroneous. See Latreille, in Cuvier, Regne Animal, vol. iv. pp. 297, 298.

La prédominance du foie avant la naissance" is noticed by Bichat (Anatomie Générale, vol. 11. p. 272), and by many other physiologists; but Dr. Elliotson appears to have been one of the first to understand a fact, the explanation of which we might vainly seek for in the earlier writers. The hypothesis, that one great use of the liver was, like that of the lungs, to remove carbon from the system, with this difference, that the alteration of the capacity of the air caused a reception of caloric into the blood, in the case of the lungs, while the hepatic excretion takes place without introduction of caloric, was, I recollect, a great favourite with me when a student. .... The Heidelberg professors have adduced many arguments to the same effect. In the foetus, for whose temperature the mother's heat must be sufficient, the lungs perform no function; but the liver is of great size, and bile is secreted abundantly, so that the meconium accumulates considerably during the latter months of pregnancy." Elliotson's Human Physiology, 1840, p. 102, In Lepelletier's Physiologie Médicale, vol. i. p. 466, vol. ii. pp. 14, 546 550, all this is sadly confused. The liver is the first-formed organ in the embryo. It is developed from the alimentary canal, and at about the third week fills the whole abdomen, and is one half the weight of the entire embryo.. At birth it is of very large size, and occupies the whole upper part of the The liver diminishes rapidly after birth, probably from obliteration of the umbilical vein." Wilson's Human Anatomy, 1851, p. 688. Compare Burdach's Physiologie, vol. iv. p. 447, where it is said of the liver in childhood, "Cet organe croit avec lenteur, surtout compara tivement aux poumons; le rapport de ceux-ci au foie étant à peu près de 1: 8 avant la respiration, il était de 1: 186 après l'établissement do cette dernière fonction." See also p. 91, and vol. fil. p. 483; and on the predominance of the liver in fatal life, see the remarks of Serres (Geoffroy Saint Hilaire, Anomalies de l'Organisation, vol. ii. p. 11), whose generalization is perhaps a little premature.

abdomen.

appear tedious to readers uninterested in physiological pursuits; but the investiga. tion has become necessary, on account of the difficulties raised by experimenters, who, not having studied the subject comprehensively, object to certain parts of it To mention what, from the ability and reputation of the author, is a conspicuous instance of this, Sir Benjamin Brodie has recently published a volume (Physiological Researches, 1851) containing some ingeniously contrived experiments on dogs and rabbits, to prove that heat is generated rather by the nervous system than by the respiratory organs. Without following this eminent surgeon into all his details, I may be permitted to observe, 1st, That as a mere matter of history, no great physiological truth has ever yet been discovered, nor has any great physiological fallacy been destroyed, by such limited experiments on a single class of animals; and this is partly because in physiology a crucial instance is impracticable, owing to the fact that we deal with resisting and living bodies, and partly because every experiment produces an abnormal condition, and thus lets in fresh causes, the operation of which is incalculable; unless, as often happens in the inorganic world, we can control the whole phenomenon. 2d, That the other department of the organic world, namely, the vegetable kingdom, has, so far as we are aware, no nervous system, but nevertheless possesses heat; and we moreover know that the heat is a product of oxygen and carbon (see note 32 to chapter ii.). 3d, That the evidence of travellers respecting the different sorts of food, and the different quantities of food, used in hot countries and in cold ones, is explicable by the respiratory and chemical theories of the origin of animal heat, but is inexplicable by the theory of the nervous origin of heat.

CHAPTER III.

EXAMINATION OF THE METHOD BY METAPHYSICIANS FOR DISCOVERING MENTAL LAWS.

THE evidence that I have collected, seems to establish two leading facts, which, unless they can be impugned, are the necessary basis of universal history. The first fact is, that in the civilizations out of Europe, the powers of nature have been far great than in those of Europe. The second fact is, that those powers have worked immense mischief; and that while one division of them has caused an unequal distribution of wealth, another division of them has caused an unequal distribution of thought, by concentrating attention upon subjects which inflame the imagination. So far as the experience of the past can guide us, we may say, that in all the extra-European civilizations, these obstacles were insuperable; certainly no nation has ever yet overcome them. But Europe, being constructed upon a smaller plan than the other quarters of the world-being also in a colder region, having a less exuberant soil, a less imposing aspect, and displaying in all her physical phenomena much greater feebleness-it was easier for Man to discard the superstitions which Nature suggested to his imagination; and it was also easier for him to effect, not, indeed, a just division of wealth, but something nearer to it, than was practicable in the older countries.

Hence it is that, looking at the history of the world as a whole, the tendency has been, in Europe, to subordinate nature to man; out of Europe, to subordinate man to nature. To this there are in barbarous countries, several exceptions; but in civilized countries the rule has been universal. The great division, therefore, between European civilization and non-European civilization, is the basis of the philosophy of history, since it suggests the important consideration, that if we would understand, for instance, the history of India, we must make the external world our first study, because it has influenced man more than man has influenced it. If, on the other hand, we would

understand the history of a country like France or England, we must make man our principal study, because nature being comparatively weak, every step in the great progress has increased the dominion of the human mind over the agencies of the external world. Even in those countries where the power of man has reached the highest point, the pressure of nature is still immense; but it diminishes in each succeeding generation, because our increasing knowledge enables us not so much to control nature, as to foretell her movements, and thus obviate many of the evils she would otherwise occasion. How successful our efforts have been, is evident from the fact, that the average duration of life constantly becomes longer, and the number of inevitable dangers fewer; and what makes this the more remarkable is, that the curiosity of men is keener, and their contact with each other closer, than in any former period; so that while apparent hazards are multiplied, we find from experience that real hazards are, on the whole, diminished.1

If, therefore, we take the largest possible view of the history of Europe, and confine ourselves entirely to the primary cause of its superiority over other parts of the world, we must resolve it into the encroachment of the mind of man upon the organic and inorganic forces of nature. To this all other causes are subordinate. For we have seen that wherever the powers of nature reached a certain height, the national civilization was irregularly developed, and the advance of the civilization stopped. The first essential was, to limit the interference of these physical phenomena; and that was most likely to be accomplished where the phenomena were feeblest and least imposing. This was the case with Europe; it is accordingly in Europe alone, that man has really succeeded in taming the energies of nature, bending them

This diminution of casualties is undoubtedly one cause, though a slight one, of the increased duration of life; but the most active cause is a general improvement in the physical condition of man: see Sir B. Brodie's Lectures on Pathology and Surgery, p. 212; and for proof that civilized men are stronger than uncivilized ones, see Quetelet sur l'Homme, vol. ii. pp. 67, 272; Lawrence's Lectures on Man, pp. 275, 276; Ellis's Polynesian Researches, vol. i. p. 98; Whately's Lectures on Political Economy, 8vo, 1831, p. 59; Journal of the Statistical Society, vol. xvii. pp. 32, 33; Dufau, Traité de Statistique, p. 107; Hawkins's Medical Statistics, p. 232.

2 The general social consequences of this I shall hereafter consider; but the mere economical consequences are well expressed by Mr. Mill: "Of the features which characterize this progressive economical movement of civilized nations, that which first excites attention, through its intimate connexion with the phenomena of Production, is the perpetual, and, so far as human foresight can extend, the unlimited growth of man's power over nature. Our knowledge of the properties and laws of physical objects shows no sign of approaching its ultimate boundaries; it is advancing more rapidly, and in a greater number of directions at once, than in any previous age or generation, and affording such frequent glimpses of unexplored fields beyond, as to justify the belief that our acquaintance with nature is still almost in its infancy." Mill's Principles of Political Economy, vol. ii. pp. 246-7.

to his own will, turning them aside from their ordinary course, and compelling them to minister to his happiness, and subserve the general purposes of human life.

All around us are the traces of this glorious and successful struggle. Indeed, it seems as if in Europe there was nothing man feared to attempt. The invasions of the sea repelled, and whole provinces, as in the case of Holland, rescued from its grasp; mountains cut through, and turned into level roads; soils of the most obstinate sterility becoming exuberant, from the mere advance of chemical knowledge: while, in regard to electric phenomena, we see the subtlest, the most rapid, and the most mysterious of all forces, made the medium of thought, and obeying even the most capricious behests of the human mind.

3

In other instances, where the products of the external world have been refractory, man has succeeded in destroying what he could hardly hope to subjugate. The most cruel dieases, such as the plague, properly so called, and the leprosy of the Middle Ages, have entirely disappeared from the civilized parts of Europe; and it is scarcely possible that they should ever again be seen there. Wild beasts and birds of prey have been extirpated, and are no longer allowed to infest the haunts of civilized men. Those frightful famines, by which Europe used to be ravaged several times in every century, have ceased; and so successfully have we grappled with them, that there is not the slightest fear of their ever returning with any thing like their former severity. Indeed, our resources are now so great, that we could, at worst, only suffer from a slight and temporary scarcity; since in the present state of knowledge, the evil would be met at the outset by remedies which chemical science could easily suggest.5

4

It is hardly necessary to notice how, in numerous other instances, the progress of European civilization has been marked

What this horrible disease once was, may be estimated from the fact, "qu'au treizième siècle on comptait en France seulement, deux mille leproseries, et que l'Europe entière renfermait environ dix neuf mille établissemens semblables." Sprengel, Histoire de la Médicine, vol. ii. p. 374. As to the mortality caused by the plague, see Clot-Bey de la Peste, Paris, 1840, pp. 62, 63, 185, 292.

For a curious list of famines, see an essay by Mr. Farr, in Journal of the Statistical Society, vol. ix. pp. 159-163. He says, that in the eleventh, twelfth, and thirteenth centuries, the average was, in England, one famine every fourteen years.

In the opinion of one of the highest living authorities, famine is, even in the present state of chemistry, "next to impossible." Herschel's Discourse on Natural Philosophy, p. 65. Cuvier (Recueil des Eloges, vol. i. p. 10) says that we have succeeded "à rendre toute famine impossible." See also Godwin on Population, p. 500; and for a purely economical argument to prove the impossibility of famine, see Mill's Principles of Political Economy, vol. ii. p. 258; and compare a note in Ricardo's Works, p. 191. The Irish famine may seem an exception; but it could have been easily baffled except for the poverty of the people, which frustrated our efforts to reduce it to a dearth.