[802] The account of these experiments was read before the Royal Society of Edinburgh in 1805, and is printed in their Transactions, vol. vi. pp. 71–185, Edinb. 1812, 4to. The general result was (pp. 148, 149), ‘That a pressure of 52 atmospheres, or 1700 feet of sea, is capable of forming a limestone in a proper heat; That under 86 atmospheres, answering nearly to 3000 feet, or about half a mile, a complete marble may be formed; and lastly, That, with a pressure of 173 atmospheres, or 5700 feet, that is little more than one mile of sea, the carbonate of lime is made to undergo complete fusion, and to act powerfully on other earths.’ See also p. 160: ‘The carbonic acid of limestone cannot be constrained in heat by a pressure less than that of 1708 feet of sea.’ There is a short, and not very accurate, notice of these instructive experiments in Bakewell's Geology, London, 1838, pp. 249, 250.
[803] As Sir James Hall says, ‘The truth of the most doubtful principle which Dr. Hutton has assumed, has thus been established by direct experiment.’ Transactions of the Royal Society of Edinburgh, vol. vi. p. 175.
[804] See the remarks of Sir James Hall, in Transactions, vol. vi. pp. 74, 75. He observes that Hutton's ‘system, however, involves so many suppositions, apparently in contradiction to common experience, which meet us on the very threshold, that most men have hitherto been deterred from an investigation of its principles, and only a few individuals have justly appreciated its merits.’ … ‘I conceived that the chemical effects ascribed by him to compression, ought, in the first place, to be investigated.’ … ‘It occurred to me that this principle was susceptible of being established in a direct manner by experiment, and I urged him to make the attempt; but he always rejected this proposal, on account of the immensity of the natural agents, whose operation he supposed to lie far beyond the reach of our imitation; and he seemed to imagine that any such attempt must undoubtedly fail, and thus throw discredit on opinions, already sufficiently established, as he conceived, on other principles.’
[805] It may be traced back, certainly to the beginning of the seventeenth century, and probably still higher. Yet the popular opinion seems to be correct, that Watt was its real inventor; though, of course, he could not have done what he did, without his predecessors. This, however, may be said of all the most eminent and successful men, as well as of the most ordinary men.
[806] On the obligations of Watt to Black, compare Brougham's Life of Watt (Brougham's Works, vol. i. pp. 25, 36–38, edit. Glasgow, 1855), with Muirhead's Life of Watt, second edit. London, 1859, pp. 66, 83. At p. 301, Mr. Muirhead says of Watt, that ‘his principal inventions connected with the steam-engine, with all their prodigious results, were founded, as we have seen, on the attentive observation of great philosophical truths; and the economy of fuel, increase of productive power, and saving of animal labour, which gradually ensued, all originated in the sagacious and careful thought with which he investigated the nature and properties of heat.’ But whatever investigations Watt made into heat, he discovered no new law respecting it, or, at all events, no new law which is large enough to be noted in the history of thermotics, considered purely as a science, and apart from practical application. Mr. Muirhead, in his interesting work which I have just quoted, has published (pp. 484–486) some remarks made on the subject by Watt, several years after the death of Black, which, though perfectly fair and candid, show that Watt had a rather confused notion of the real difference between an invention and a discovery.
[807] Mr. Muirhead, in his Life of Watt, pp. 301–370, seems to have put the priority of Watt beyond further doubt; though he is somewhat hard upon Cavendish, who, there can be little question, made the discovery for himself.
[808] I would not wish to diminish one jot of the veneration in which the great name of Watt is justly held. But when I find the opinion of Dr. Withering, the botanist, quoted, to the effect that his ‘abilities and acquirements placed him next, if not superior, to Newton.’ (Muirhead's Life of Watt, p. 302), I cannot but protest against such indiscriminate eulogy, which would rank Watt in the same class as one of those godlike intellects of which the whole world has not produced a score, and which are entitled to be termed inspired, if ever human being was so. Another instance of this injudicious panegyric will be found in the same otherwise excellent work (Muirhead, pp. 324, 325), where we read that Watt's discovery that water consists of oxygen and hydrogen, was ‘the commencement of a new era, the dawn of a new day in physical inquiry, the real foundation of the new system of chemistry; nay, even a discovery “perhaps of greater importance than any single fact which human ingenuity has ascertained either before or since.”’
[809] That there was no plagiarism on the part of Watt, we know from positive evidence; that there was none on the part of Cavendish, may be fairly presumed, both from the character of the man, and also from the fact that in the then state of chemical knowledge the discovery was imminent, and could not have been long delayed. It was antecedently probable that the composition of water would be ascertained by different persons at the same time, as we have seen in many other discoveries which have been simultaneously made, when the human mind, in that particular department of inquiry, had reached a certain point. We are too apt to suspect philosophers of stealing from each other, what their own abilities are sufficient to work out for themselves. It is, however, certain that Watt thought himself ill-treated by Cavendish. See Watt's Correspondence on the Composition of Water, London, 1846, pp. 48, 61.
[810] On 26th November 1783, he writes: ‘For many years I have entertained an opinion that air was a modification of water; which was originally founded on the facts, that in most cases where air was actually made, which should be distinguished from those wherein it is only extricated from substances containing it in their pores, or otherwise united to them in the state of air, the substances were such as were known to contain water as one of their constituent parts, yet no water was obtained in the processes, except what was known to be only loosely connected with them, such as the water of the crystallization of salts. This opinion arose from a discovery that the latent heat contained in steam diminished, in proportion as the sensible heat of the water from which it was produced, increased; or, in other words, that the latent heat of steam was less when it was produced under a greater pressure, or in a more dense state, and greater when it was produced under a less pressure, or in a less dense state; which led me to conclude, that when a very great degree of heat was necessary for the production of the steam, the latent heat would be wholly changed into sensible heat; and that, in such cases, the steam itself might suffer some remarkable change. I now abandon this opinion, in so far as relates to the change of water into air, as I think that may be accounted for on better principles.’ See this remarkable passage, which is quite decisive as to the real history of Watt's discovery, in Correspondence of James Watt on the Composition of Water, London, 1846, pp. 84, 85. Compare p. cxxiv. and p. 248 note.
[811] In the paper which he communicated to the Royal Society, announcing his discovery, he, well knowing the empirical character of the English mind, apologizes for this; and says, ‘I feel much reluctance to lay my thoughts on these subjects before the public in their present indigested state, and without having been able to bring them to the test of such experiments as would confirm or refute them.’ Watt's Correspondence on the Discovery of the Composition of Water, pp. 77, 78. Eleven months earlier, that is in December 1782, he writes (Ibid. p. 4): ‘Dr. Priestley has made a most surprising discovery, which seems to confirm my theory of water's undergoing some very remarkable change at the point where all its latent heat would be changed into sensible heat.’
[812] ‘He’ (i.e. Cavendish) ‘here omits entirely the consideration of latent heat; an omission which he even attempts to justify, in one of the passages interpolated by Blagden. But it is well known to every one acquainted with the first principles of chemical science, even as it was taught in the days of Black, and it was indisputably familiar to Mr. Watt, that no aëriform fluid can be converted into a liquid, nor any liquid into a solid, without tho evolution of heat, previously latent. This essential part of the process, Mr. Cavendish's theory does not embrace; but without it, no theory on the subject can be complete; and it will presently be seen, that Mr. Watt took it fully into account.’ Muirhead's Life of Watt, p. 315.
[813] ‘Cavendish and Watt both discovered the composition of water. Cavendish established the facts; Watt the idea.’ … ‘The attaching too high a value to the mere facts, is often a sign of a want of ideas.’ Liebig's Letters on Chemistry, London, 1851, p. 48. The last sentence of this illustrious philosopher, which I have put in italics, should be well pondered in England. If I had my way, it should be engraved in letters of gold over the portals of the Royal Society and of the Royal Institution.
[814] ‘Organic substances, whether directly derived from the vegetable or animal kingdom, or produced by the subsequent modification of bodies which thus originate, are remarkable as a class for a degree of complexity of constitution far exceeding that observed in any of the compounds yet described.’ Fownes' Chemistry, 3rd edit., London, 1850, p. 353. I quote this, as the first authority at hand, for a doctrine which is universally admitted by chemists, and which is indubitably true, so far as our experiments have at present extended.
[815] ‘As the organic world is characterized by the predominance, in quantity, of carbon, so the mineral or inorganic world is marked by a similar predominance of silicon.’ Turner's Chemistry, edited by Liebig and Gregory, vol. ii. p. 678, London, 1847.
[816] I mean, of course, to apply this remark only to the globe we inhabit, and not to extra-terrestrial phenomena. Respecting the organization or non-organization of what exists out of this earth, we have no evidence, and can hardly expect to have any for centuries. Inferences have, indeed, been drawn from telescopic observations; and attempts are now being made, abroad, to determine, by a still more refined process, the physical composition of some of the heavenly bodies. But without venturing, in this note, to enter into such discussions, or even to state their purport, I may say, that the difficulty of verification will long prove an insuperable barrier to our knowledge of the truth or falsehood of any results which may be obtained.
[817] Mr. Simon, in his thoughtful and suggestive Lectures, says, ‘We may describe Pathology to consist in the Science of Life under other conditions than those of ideal perfection.’ Simon's Lectures on Pathology, London, 1850, p. 14. This is by far the best description I have met with; though, as it involves a negative, it cannot be accepted as a definition. Indeed, the context shows that Mr. Simon does not suppose it to be one.
[818] I formerly adopted the commonly received division of organic statics, and organic dynamics; the statics being anatomy, and the dynamics being physiology. But, I now think that our knowledge is not sufficiently advanced to make this so convenient as the division into physiological and pathological, or into normal and abnormal, provided we remember that in reality nothing is abnormal. The practically useful, but eminently unscientific, doctrine, that there can be alteration of function without alteration of structure, has effaced some of the most essential distinctions between anatomy and physiology, and especially between morbid anatomy and morbid physiology. Until those distinctions are recognized, the scientific conceptions of professional writers must be confused, however valuable their practical suggestions may be. While men are capable of believing that it is possible for variations of function to proceed from any cause except variations of structure, the philosophic importance of anatomy will be imperfectly appreciated, and its true relation to physiology will remain undefined. Inasmuch, however, as, with our actual resources, the most careful dissection is often unable to detect (in insanity, for instance) those changes of structure which produce changes of function, superficial thinkers are placed under a strong temptation to deny their invariable connexion; and while the microscope is so imperfect, and chemistry so backward, it is impossible that experiments should always convince them of their mistake. Hence, I believe that until our means of empirical research are greatly improved, all such investigations, notwithstanding their immense value in other respects, will tend to lead mere inductive minds into error, by making them rely too much on what they call the facts of the case, to the prejudice of the reason. This is what I mean by saying, that our knowledge is not sufficiently advanced to make it advisable to divide the sciences of organic bodies into physiological and anatomical. At present, and probably for some time yet, the humbler division into physiological and pathological, may be deemed safer, and more likely to produce solid results.
[819] Hunter, as we shall presently see, did take an extraordinarily comprehensive view of pathology, including the whole of the organic world and even the aberrations of form in the inorganic.
[820] Thomson's Life of Cullen, vol. i. p. 70, Edinburgh, 1832.
[821] Thomson's Life of Cullen, vol. i. p. 96. Bower states that Cullen ‘was appointed to the chair in 1755.’ Bower's History of the University of Edinburgh, vol. ii. p. 216, Edinburgh, 1817.
[822] ‘It seems impossible to peruse the passages I have quoted from Dr. Cullen's manuscript lectures and papers, and from his Essay on Evaporation, without perceiving that his investigations with regard to the heat and cold occasioned by the combination, liquefaction, and evaporation of bodies, must not only have assisted to direct the attention of his pupil Dr. Black to similar inquiries, but must also have furnished him with several of the data from which his simple and comprehensive theory of Latent Heat was afterwards so philosophically deduced.’ Thomson's Life of Cullen, vol. i. p. 56.
[823] ‘It is allowed by the admirers of this great man, that he was perhaps too fond of theory.’ Bower's History of the University of Edinburgh, vol. iii. p. 273
[824] In 1759, he wrote to Dr. Balfour Russell, one of his favourite pupils: ‘You will not find it possible to separate practice from theory altogether; and therefore, if you have a mind to begin with the theory, I have no objection.’ Thomson's Life of Cullen, vol. i. p. 130. Compare his Introductory Lectures to the Practice of Physic, where, asserting truly, ‘that reasoning in physic is unavoidable’ (Cullen's Works, vol. i. p. 417), he boldly infers, ‘that to render it safe, it is necessary to cultivate theory in its full extent.’
[825] Even Cullen himself says, rather roughly, ‘The great horde of physicians are always servile imitators, who can neither perceive nor correct the faults of their system, and are always ready to growl at, and even to worry, the ingenious person that could attempt it. Thus was the system of Galen secured in the possession of the schools of physic, till soon after the irruption of the Goths and Vandals destroyed every vestige of literature in the western parts of Europe, and drove all that remained of it to seek a feeble protection at Constantinople.’ Lectures Introductory to the Practice of Physic, in Cullen's Works, vol. i. p. 386, Edinburgh, 1827.
[826] This idea runs through the whole of his writings. In the following passage, it is more succinctly stated than in any other: ‘In pathology, and in the prognosis of particular diseases, it is absolutely necessary to enter into the distinction of these causes. I call the one direct causes, those which act upon the nervous system directly; and the other indirect causes, those which produce the same effect, but by destroying those organs which are necessary to the support of the excitement, viz. the whole system of circulation.’ Cullen's Works, vol. i. p. 135. Even this passage, clear as it seems, can only be rightly interpreted by taking the context into consideration.
[827] For, as is truly observed by probably the greatest pathologist of our time, ‘Humoral pathology is simply a requirement of common practical sense; and it has always held a place in medical science, although the limits of its domain have, no doubt, been variously circumscribed or interpreted at different times. Of late years, it has met with a new basis and support in morbid anatomy, which, in the inadequacy of its discoveries in the solids to account for disease and death, has been compelled to seek for an extension of its boundary through a direct examination of the blood itself.’ Rokitansky's Pathological Anatomy, vol. i. p. 362, London, 1854.
[828] Unless, as is the case in geometry, the premisses, which are suppressed, are so slight as to be scarcely perceptible.
[829] He was so indignant at the bare idea of a humoral pathology, that even Hoffmann, who before himself was the most eminent advocate of solidism, fell under his displeasure for allowing some little weight to the humoral doctrines. He says that Hoffmann ‘has not applied his fundamental doctrine so extensively as he might have done; and he has everywhere intermixed an humoral pathology, as incorrect and hypothetical as any other.’ Cullen's Works, vol. i. p. 410. At p. 470, ‘I have, therefore, assumed the general principles of Hoffmann. And, if I have rendered them more correct, and more extensive in their application, and, more particularly, if I have avoided introducing the many hypothetical doctrines of the Humoral Pathology which disfigured both his and all the other systems that have hitherto prevailed, I hope I shall be excused for attempting a system, which, upon the whole, may appear new.’
[830] ‘The solid parts of the body seem to be of two kinds: one whose properties are the same in the dead as in the living, and the same in the animate as in many inanimate bodies; the other, whose properties appear only in living bodies. In the last, a peculiar organization, or addition, is supposed to take place; in opposition to which the first are called the simple solids. Of these only, we shall treat here; and of the others, which may be called vital solids, being the fundamental part of the nervous system, we shall treat under that title in the following section.’ Cullen's Works, vol. i. p. 10.
[831] These diseases are laxity, flaccidity, &c. See the enumeration of ‘the diseases of the simple solids,’ in Cullen's Works, vol. i. p. 14.
[832] Cullen's Works, vol. i. pp. 65, 600, vol. ii. p. 364. Dr. Thomson, who had access to papers and lectures of Cullen's, which have never been published, says (Life of Cullen, vol. i. p. 265), ‘His speculations with regard to the different functions of the nervous system, but more particularly with regard to that of the Animal Power or Energy of the brain, were incorporated with every opinion which he taught concerning the phenomena of the animal economy, the causes of diseases, and the operation of medicines; and they may be said to constitute a most important part, if not the sole basis, of that system of the Practice of Physic, which he made the subject of prelection, as well as of study, for a period of nearly forty years, before he ventured to give it to the public.’ I should mention, that Cullen, under the term ‘brain,’ included the contents of the vertebral column as well as of the cranium.
[833] Cullen's Works, vol. i. pp. 40, 546, 558, 648, vol. ii. p. 321.
[834] Cullen's Works, vol. i. pp. 86, 91, 100, 101, 108, 115, 116, 553, 592, vol. ii. pp. 35, 366. Compare the summary of causes in Thomson's Life of Cullen, vol. i. p. 289.
[835] He says (Works, vol. i. pp. 31, 32), ‘Whoever has the smallest tincture of metaphysics will know the distinction pointed at here between the qualities of bodies as primary and secondary.’ … ‘Whether these distinctions be well or ill founded, it is not my business to inquire.’ But though he did not deem it his business to inquire into the accuracy of these and similar distinctions, he thought himself justified in assuming them, and reasoning from them as if they could explain the working of those sensations, whose perversion formed the point of contact between metaphysics and pathology. See, for instance, in his Works, vol. i. p. 46, the long series of unproved and improvable assertions respecting the combination and comparison of sensations giving rise to memory, imagination, and the like.
[836] Cullen, with that admirable candour which was one of the most attractive peculiarities of his fine intellect, confesses his want of acquaintance with the microscope: ‘It leaves me, who am not conversant in such observations, altogether uncertain with respect to the precise nature of this part of the blood.’ Cullen's Works, vol. i. p. 195. A pathologist without a microscope is an unarmed man, indeed. In regard to his animal chemistry, one passage may be quoted as a specimen of the manner in which he arrived at conclusions speculatively, instead of subjecting the phenomena to experimental investigation. ‘We may remark it to be highly probable, that all animal matter is originally formed of vegetable; because all animals either feed directly and entirely on vegetables, or upon other animals that do so. From hence it is probable, that all animal substances may be traced to a vegetable origin; and therefore, if we would inquire into the production of animal matter, we must first inquire in what manner vegetable matter may be converted into animal?’ Cullen's Works, vol. i. pp. 177, 178. The therefore and the must, resulting merely from an antecedent probability, are characteristic of that over-boldness, into which deduction is apt to degenerate, and which is strongly contrasted with the opposite vice of over-timidity, by which inductive reasoners are tainted.
[837] Dr. Watson (Principles and Practice of Physic, 4th edit. London, 1857, vol. i. p. 41) says of the humoral pathology, that, ‘the absurdity of the hypothesis, and still more the dangerous practice which this doctrine generated, began to be manifest, and led to its total abandonment.’ But, with every respect for this eminent authority, I venture to observe, that this supposition of Dr. Watson's is contradicted by the whole history of the human mind. There is no well-attested case on record of any theory having been abandoned, because it produced dangerous results. As long as a theory is believed, men will ascribe its evil consequences to any cause except the right one. And a theory which is once established, will always be believed, until there is some change in knowledge which shakes its foundation. Every practical change may, by careful analysis, be shown to depend, in the first instance, on some change of speculative opinions. Even at the present day, many doctrines are generally held in the most civilized countries, which are producing dangerous practical consequences, and have produced those consequences for centuries. But the mischief which the doctrine engenders does not weaken the doctrine itself. Nothing can do that, but the general progress of knowledge, which, by altering former opinions, modifies future conduct.
[838] Some writers, who have taken notice of Cullen, have been deceived in this respect by his occasional use of the expression ‘nervous fluid,’ as if he were willing to let in the idea of humorism. But, in one place, he distinctly guards himself against such misconstruction. ‘Now, to avoid determining any thing with regard to these opinions, I have used the term of nervous power; but as this is a little ambiguous, I choose to express it by nervous fluid; not that I suppose, with Dr. Boerhaave, that the brain is an excretory, and that a fluid is secreted from it: I mean nothing more than that there is a condition of the nerves which fits them for the communication of motion. But I defer the consideration of these opinions for the present, and perhaps ad Græcas calendas; but nothing shall be rested upon the nervous fluid, it shall be considered merely as a power fitted for communicating motions.’ Cullen's Works, vol. i. p. 17. Without this passage, his remarks on ‘the nervous fluid in the brain’ (Works, vol. i. p. 129), might easily be misunderstood.
[839] ‘Together with this, the languor, inactivity, and debility of the animal motions, the imperfect sensations, the feeling of cold, while the body is truly warm, and some other symptoms, all show that the energy of the brain is, on this occasion, greatly weakened; and I presume that, as the weakness of the action of the heart can hardly be imputed to any other cause, this weakness also is a proof of the diminished energy of the brain. So I conclude, that a debility of the nervous power forms the beginning of the cold fit, and lays the foundation of all the other phenomena.’ Practice of Physic, in Cullen's Works, vol. i. p. 492.
[840] ‘To render our doctrine of fever consistent and complete, it is necessary to add here, that these remote causes of fever, human and marsh effluvia, seem to be of a debilitating or sedative quality.’ … ‘Though we have endeavoured to show that fevers generally arise from marsh or human effluvia, we cannot, with any certainty, exclude some other remote causes, which are commonly supposed to have at least a share in producing those diseases. And I proceed, therefore, to inquire concerning these causes; the first of which that merits attention, is the power of cold applied to the human body.’ … ‘Besides cold, there are other powers that seem to be remote causes of fever; such as fear, intemperance in drinking, excess in venery, and other circumstances, which evidently weaken the system. But whether any of these sedative powers be alone the remote cause of fever, or if they only operate either as concurring with the operation of marsh or human effluvia, or as giving an opportunity to the operation of cold, are questions not to be positively answered.’ Practice of Physic, in Cullen's Works, vol. i. pp. 546, 552. One part of this view has been corroborated, since the time of Cullen. ‘The experiments of Chossat and others clearly prove cold to be a direct sedative.’ Williams' Principles of Medicine, 2nd edit. London, 1848, p. 11. Compare Watson's Principles and Practice of Physic, 4th edit. London, 1857, vol. i. pp. 87–92, 249. Hence, perhaps, the ‘irresistible tendency to sleep caused by exposure to severe or long-continued cold.’ Erichsen's Surgery, 2nd edit. London, 1857, p. 336; but as to this, Dr. Watson (Principles of Physic, vol. i. p. 89) is sceptical, and thinks that, in those cases which are recorded, the drowsiness ascribed to cold, is, in a great measure, the result of fatigue.
[841] Cullen's Works, vol. i. p. 493. Compare, respecting his general theory of spasm, p. 84, and vol. ii. p. 400.
[842] ‘The idea of fever, then, may be, that a spasm of the extreme vessels, however induced, proves an irritation to the heart and arteries; and that this continues till the spasm is relaxed or overcome.’ Cullen's Works, vol. i. p. 494.
[843] ‘Such, however, is, at the same time, the nature of the animal economy, that this debility proves an indirect stimulus to the sanguiferous system; whence, by the intervention of the cold stage and spasm connected with it, the action of the heart and larger arteries is increased, and continues so till it has had the effect of restoring the energy of the brain, of extending this energy to the extreme vessels, of restoring, therefore, their action, and thereby especially overcoming the spasm affecting them; upon the removing of which, the excretion of sweat, and other marks of the relaxation of excretories, take place.’ Practice of Physic, in Cullen's Works, vol. i. pp. 501, 502. See also p. 636, § cciii. Or, as he elsewhere expresses himself (vol. i. p. 561): ‘With regard to the event of fevers, this is the fundamental principle: in fevers, nature cures the disease; that is, certain motions tending to death continue the disease, but, in consequence of the laws of the animal economy, other motions are excited by these which have a tendency to remove it.’
[844] ‘If we may trust to our conclusions with respect to the proximate cause, it follows, most naturally, from the view there given, that the continued fever is always owing to an excess of spasm, or to an excess of debility: as the one or other of these prevails, it will give one or other of the two forms, either the Synocha or inflammatory fever, or the Typhus or nervous fever.’ Cullen's Works, vol. i. p. 518.
[845] ‘Cullen's most esteemed work is his Nosology.’ Hamilton's History of Medicine, London, 1831, vol. ii. p. 279. ‘His Nosology will probably survive all his other works; it is indisputably the best system which has yet appeared.’ Lives of British Physicians, London, 1830, p. 213. ‘Celle de Cullen, qui parut en 1772, et qui constitue un véritable progrès.’ Renouard, Histoire de la Médecine, Paris, 1846, vol. ii. p. 231. See also Hooper's Medical Dictionary, edited by Dr. Grant, London, 1848, p. 937. But, in the most celebrated medical works which have appeared in England during the last twelve or fifteen years, I doubt if there is any instance of the adoption of Cullen's nosological arrangement. Abroad, and particularly in Italy, it is more valued.
[846] ‘I had rather not be cramped and hampered by attempting what abler heads than mine have failed to achieve, and what, in truth, I believe, in the present state of our science, to be impossible, a complete methodical system of nosology.’ Watson's Principles and Practice of Physic, London, 1857, vol. i. p. 9. This is the wisdom of a powerful understanding.
[847] ‘Now, when the diseases of Cullen's nosology have been almost doubled, and the facts relating to them have been more than doubled.’ Williams' Principles of Medicine, London, 1848, p. 522.
[848] I had intended giving some account of the once celebrated Brunonian system, which was founded by Dr. John Brown, who was first the pupil of Cullen, and afterwards his rival. But a careful perusal of his works has convinced me that the real basis of his doctrine, or the point from which he started, was not pathology, but therapeutics. His hasty division of all diseases into sthenic and asthenic, has no claim to be deemed a scientific generalization, but was a mere artificial arrangement, resulting from a desire to substitute a stimulating treatment in the place of the old lowering one. He, no doubt, went to the opposite extreme; but that being a purely practical subject, this Introduction has no concern with it. For the same reason, I omit all mention of Currie, who, though an eminent therapeutician, was a commonplace pathologist. That so poor and thinly-peopled a country as Scotland, should, in so short a period, have produced so many remarkable men, is extremely curious.
[849] Mr. Ottley (Life of Hunter, p. 186) says, ‘In his writings we occasionally find an obscurity in the expression of his thoughts, a want of logical accuracy in his reasonings, and an incorrectness in his language, resulting from a deficient education.’ But, a deficient education will never make a man obscure. Neither will a good education make him lucid. The only cause of clearness of expression is clearness of thought; and clearness of thought is a natural gift, which the most finished and systematic culture can but slightly improve. Uneducated men, without a thousandth part of John Hunter's intellect, are often clear enough. On the other hand, it as frequently happens that men, who have received an excellent education, cannot speak or write ten consecutive sentences which do not contain some troublesome ambiguity. In Hunter's works such ambiguities are abundant; and this is probably one of the reasons why no one has yet given a connected view of his philosophy. On his obscurity, compare Cooper's Life of Sir Astley Cooper, London, 1843, vol. i. pp. 151, 152; Paget's Lectures on Surgical Pathology, London, 1853, vol. i. p. 419; and the remarks of his enemy, Foot, in Foot's Life of Hunter, London, 1794, p. 59.
[850] He was born in 1728, and came to London in 1748. Adams' Life of John Hunter, 2nd edit. London, 1818, pp. 20, 203. According to Adams (pp. 30–35), he was abroad as surgeon in the English army from 1761 to 1763; though, in Foot's Life of Hunter, London, 1794, p. 78, he is said to have returned to England in 1762. Mr. Ottley says that he returned in 1763. Ottley's Life of Hunter, p. 22, in vol. i. of Hunter's Works, edited by Palmer, London, 1835.
[851] See Buckle's History of Civilization, vol. ii. pp. 374, 375.
[852] ‘He followed his natural inclination. He preferred the more delusive, apparently the more direct, road, which has seduced so many philosophers. He sought to arrive at the general laws of nature at once by conjecture: rather than, by a close and detailed study of her inferior operations, to ascend, step by step, through a slow and gradual induction to those laws which govern her general procedure.’ Babington's Preface to Hunter's Treatise on the Venereal Disease, in Hunter's Works, vol. ii. p. 129. Compare the narrow and carping criticism in Foot's Life of Hunter, p. 163.
[853] That I may not be suspected of exaggeration, I will quote what by far the greatest of all the historians of medicine has said upon this subject. ‘La majorité des médecins qui prétendaient s'être formés d'après Bâcon, n'avaient hérité de lui qu'une répugnance invincible pour les hypothèses et les systèmes, une grande vénération pour l'expérience, et un désir extrême de multiplier le nombre des observations. Ce fut chez les Anglais que la méthode empirique en médecine trouva le plus de partisans, et c'est principalement aussi chez eux qu'elle s'est répandue jusqu'aux temps les plus rapprochés de nous. Sa propagation y fut favorisée, non-seulement par le profond respect que les Anglais continuent toujours de porter à l'immortel chancelier, mais encore par la haute importance que la nation entière attache au sens commun, common sense, et elle y demeura l'ennemie irréconciliable de tous les systèmes que ne reposent pas sur l'observation.’ Sprengel, Histoire de la Médecine, vol. v. p. 411, Paris, 1815.
[854] Clive says, ‘Much as Mr. Hunter did, he thought still more. He has often told me, his delight was, to think.’ Abernethy's Hunterian Oration, London, 1819, p. 26.
[855] Mr. Owen, in his interesting Preface to the fourth volume of Hunter's Works, says (p. vii.), ‘There is proof that Hunter anatomized at least five hundred different species of animals, exclusive of repeated dissections of different individuals of the same species, besides the dissections of plants to a considerable amount.’
[856] ‘Some idea may be formed of Hunter's extraordinary diligence, by the fact, that his museum contained, at the time of his death, upwards of 10,000 preparations, illustrative of human and comparative anatomy, physiology, and pathology, and natural history.’ Weld's History of the Royal Society, London, 1848, vol. ii. p. 92.
[857] ‘I have tested the conflicting evidence of these observers by dissection of the heart in the lobster; and you will perceive by this preparation that it is more complicated than even the Danish naturalist supposed, and fully bears out the opinion of Hunter in regard to the mixed nature of the circulation in the crustacea.’ Owen's Lectures on the Comparative Anatomy and Physiology of the Invertebrate Animals, 2nd edit. London, 1855, p. 318. ‘Cuvier, misled by the anomalous diffused condition of the venous system, supposed that there was no circulation of the blood in insects; yet the dorsal vessel was too conspicuous a structure to be overlooked. Such, however, was the authority of the great anatomist, that the nature of the heart began to be doubted, and the strangest functions to be attributed to it. Hunter, however, who was prepared to appreciate the true state of the circulating system in insects, by his discovery of the approximately diffused and irregular structure of the veins in the crustacea, has described, in his work on the blood, all the leading characters of the circulation in insects as it is recognized by comparative physiologists of the present day.’ Ibid. p. 383. Compare Hunter's Essays and Observations on Natural History, London, 1861, vol. i. p. 108.