History of Civilization in England, Vol. 3 of 3

by Henry Thomas Buckle

Another, and still more remarkable proof of the extent to which Hunter outstripped his own age, appears in the following passage, which has just been published in his posthumous works, and in which he anticipates the grandest and most suggestive of all the ideas belonging to the physiology of the nineteenth century. ‘If we were capable of following the progress of increase of the number of the parts of the most perfect animal, as they first formed in succession, from the very first to its state of full perfection, we should probably be able to compare it with some one of the incomplete animals themselves, of every order of animals in the Creation, being at no stage different from some of the inferior orders. Or, in other words, if we were to take a series of animals, from the more imperfect to the perfect, we should probably find an imperfect animal, corresponding with some stage of the most perfect.’ Essays and Observations by John Hunter, being his Posthumous Papers, London, 1861, vol. i. p. 203.

[876] ‘The natural salutary actions, arising from stimuli, take place both in animals and vegetables, and may be divided into three kinds. The first kind of action, or self-motion, is employed simply in the economical operations, by which means the immediate functions are carried on, and the necessary operations performed, with the materials the animal or vegetable is in possession of, such as growth, support, secretion, &c. The blood is disposed of by the actions of the vessels, according to their specific stimulus, producing all the above effects. The juices of a plant are disposed of according to the different actions of the sap-vessels, arising also from their specific stimulus, which is different from that of blood-vessels, but equally produces growth; but a vine will grow twenty feet in one summer, while a whale, probably, does not grow so much in as many years.’ Croonian Lectures on Muscular Motion, in Hunter's Works, vol. iv. p. 199.

[877] ‘The second kind of action is in pursuit of external influence, and arises from a compound of internal and external stimulus; it is excited by the state of the animal or vegetable, which gives the stimulus of want, and being completed by external stimulus, produces the proper supplies of nourishment. It produces motions of whole parts: thus we see the Hedysarum gyrans moving its lesser foliola. This is an action apparently similar to breathing in animals, though, perhaps, it does not answer the same purpose; yet there is an alternate motion in both.’ Croonian Lectures, in Hunter's Works, vol. iv. p. 200.

[878] ‘The third kind of motion is from external stimulus, and consists principally of the motion of whole parts, which is not inconsiderable in vegetables, as in the Dionæa muscipula and Mimosa pudica is very evident.’ … ‘These actions are similar to what arise in many animals from external stimulus.’ Ibid. vol. iv. p. 201.

[879] ‘I make a material difference between the power and the quantity of action. Some motions may be very small, yet act with great force; while others are of considerable extent, although very weak.’ Ibid. vol. iv. p. 204.

[880] ‘The immediate cause of motion in all vegetables is most probably the same, and it is probably the same in all animals; but how far they are the same in both classes, has not yet been determined. But I think it will appear, in the investigation of this subject, that vegetables and animals have actions evidently common to both, and that the causes of these actions are apparently the same in both; and most probably there is not an action in the vegetable, which does not correspond or belong to the animal, although the mode of action in the parts may not be the same, or muscular, in both.’ Croonian Lectures, in Hunter's Works, vol. iv. p. 196. Compare the section ‘Of Motion in Vegetables,’ in Hunter's Essays, London, 1861, vol. i. p. 24.

[881] ‘The variety of motions is greater in animals, and more purposes are answered by them.’ … ‘The first kind of action appears to be stronger in its power, although less in quantity, in vegetables than in animals; for a small vine was capable of sustaining, and even of raising, a column of sap 43 feet high, while a horse's heart was only capable of supporting a column of blood 8 feet 9 inches high; both of which columns must have been supported by the action of the internal parts, for we must suppose the heart equal, or nearly so, to the strength or action of the other parts of the vascular system; and when we consider that the sap of the tallest tree must be supported, and even raised from the root to the most distant branches, it must appear that the power of such vegetables far exceeds the power of any animal, and, indeed, it is such as the texture of a vegetable only can support. The power of supporting a leaf erect for a whole day is as great an effort of action as that of the elevator palpebrarum muscle of the eye of an animal.’ Hunter's Works, vol. iv. pp. 203, 204. See also Hunter's Essays, vol. i. p. 342: ‘It is probable that the vegetable which can the least bear a suspension of its actions, can do so more than the animal which can bear it longest.’

[882] Hunter's Works, vol. iv. p. 255.

[883] In his Principles of Surgery, he says (Hunter's Works, vol. i. p. 220), ‘The human body is what I mean chiefly to treat of; but I shall often find it necessary to illustrate some of the propositions which I shall lay down from animals of an inferior order, in whom the principles may be more distinct and less blended with others, or where the parts are differently constructed, in order to show, from many varieties of structure, and from many different considerations, what are the uses of the same parts in man; or, at least, to show that they are not for the uses which have been commonly assigned to them; and, as man is the most complicated part of the whole animal creation, it will be proper, in the first place, to point out general principles, common to all this species of matter, that I may be better understood when I come to the more complicated machine, namely, the human.’

[884] ‘Before we endeavour to give an idea of an animal, it is necessary to understand the properties of that matter of which an animal is composed; but the better to understand animal matter, it is necessary to understand the properties of common matter; else we shall be often applying our ideas of common matter, which are familiar to us, to animal matter, an error hitherto too common, but which we should carefully avoid.’ Principles of Surgery, in Hunter's Works, vol. i. p. 211. ‘In the natural history of vegetables and animals, therefore, it will be necessary to go back to the first or common matter of this globe, and give its general properties; then see how far these properties are introduced into the vegetable and animal operations; or rather, perhaps, how far they are of use or subservient to their actions.’ Hunter's Essays, vol. i. p. 4. ‘Every property in man is similar to some property, either in another animal, or probably in a vegetable, or even in inanimate matter. Thereby (man) becomes classible with those in some of his parts.’ Ibid. p. 10.