History of Civilization in England, Vol. 3 of 3

by Henry Thomas Buckle

[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.