there, nor in Mexico, nor in Peru, nor in Egypt, did the people desire to represent their deities in human forms, or ascribe to them human attributes. Even their temples are huge buildings, often constructed with great skill, but showing an evident wish to impress the mind with fear, and offering a striking contrast to the lighter and smaller structures which the Greeks employed for religious purposes. Thus, even in the style of architecture do we see the same principle at work; the dangers of the tropical civilization being more suggestive of the infinite, while the safety of the European civilization was more suggestive of the finite. To follow out the consequences of this great antagonism, it would be necessary to indicate how the infinite, the imaginative, the synthetic, and the deductive, are all connected; and are opposed, on the other hand, by the finite, the sceptical, the analytic, and the inductive. A complete illustration of this, would carry me beyond the plan of this Introduction, and would perhaps exceed the resources of my own knowledge; and I must now leave to the candour of the reader what I am conscious is but an imperfect sketch, but what may, nevertheless, suggest to him materials for future thought, and, if I might indulge the hope, may open to historians a new field, by reminding them that every where the hand of Nature is upon us, and that the history of the human mind can only be understood by connecting with it the history and the aspects of the material universe. seems to have been to excite terror." Stephens's Central America, vol. i. p. 152; at p. 159, "The form of sculpture most generally used was a death's head.' At Mayapan (vol. iii. p. 133), “representations of human figures, or animals with hideous features and expressions, in producing which the skill of the artist seems to have been expended;" and again, p. 412, natural and grotesque faces." 66 un NOTE 36 to p. 56. As these views have a social and economical importance quite independent of their physiological value, I will endeavour, in this note, to fortify them still further, by showing that the connexion between carbonized food and the respiratory functions may be illustrated by a wider survey of the animal kingdom. The gland most universal among the different classes of animals is the livera and its principal business is to relieve the system of its superfluous carbon, which it accomplishes by secreting bile, a highly carbonized fluid." Now, the connexion between this process and the respiratory functions is highly curious. For if we take a general view of animal life, we shall find that the liver and lungs are nearly always compensatory; that is to say, when one organ is small and inert, the other is large 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, a "The most constant gland in the animal kingdom is the liver." Grant's Comp. Anat. p. 576. See also Béclard, Anat. Gén. p. 18, and Burdach, Traité de Physiol. vol. ix. p. 580. Burdach says, "Il existe dans presque tout le règne animal ;" and the latest researches have detected the rudiments of a liver even in the Entozoa and Rotifera. Rymer Jones's Animal Kingdom, 1855, p. 183, and Ocen's Invertebrata, 1855, p. 104. b Until the analysis made by Demarçay in 1837, hardly any thing was known of the composition of bile; but this accomplished chemist ascertained that its essential constituent is choleate of soda, and that the choleic acid contains nearly sixty-three per cent of carbon. Compare Thomson's Animal Chemistry, pp. 59, 60, 412, 602, with Simon's Chemistry, vol. ii. pp. 17-21. "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. d Carus's Comparative Anatomy, vol. ii. p. 230; Grant's Comp. Anat. pp. 385, 596; Rymer Jones's Animal Kingdom, p. 646. e 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, Règne Animal, vol. iv. pp. 297, 298. f"La prédominance du foie avant la naissance" is noticed by Bichat (Anatomie Générale, vol. ii. 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 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 organization, 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 appear tedious to readers uninterested in physiological pursuits; but the investigation 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 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 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 abdomen. The liver diminishes rapidly after birth, probably from obliteration of the umbilical vein." Wilson's Human Anatomy, 1851, p. 638. Compare Burdach's Physiologie, vol. iv. p. 447, where it is said of the liver in childhood, "Cet organe croit avec lenteur, surtout comparativement aux poumons; le rapport de ceux-ci au foie étant à peu près de 1:3 avant la respiration, il était de 1:186 après l'établissement de cette dernière fonction." See also p. 91, and vol. iii. 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. confused. 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 EMPLOYED BY METAPHYSICIANS FOR 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 greater than in those in 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 |