[866] ‘The fact of the muscularity of the iris, which is here presumed from analogy by Mr. Hunter, has been since directly proved by the observations of Bauer and Jacob (Phil. Trans. 1822), and indirectly by Berzelius, who found that the iris possesses all the chemical properties of muscle.’ Palmer's note in Hunter's Works, vol. iii. p. 146, London, 1837.
[867] Adams' Life of Hunter, pp. 59, 60, 245. Hunter's Works, vol. i. p. 43, vol. iv. pp. 116–121. Watson's Principles of Physic, vol. ii. p. 440.
[868] ‘Hunter subjects the blood to both mechanical and chemical analysis, and endeavours to determine the characteristic properties of its different constituents.’ Owen's Preface to vol. iv. of Hunter's Works, p. xii. But this gives, perhaps, rather too high an idea of his animal chemistry; for such was then the miserable state of this extremely important branch of knowledge, that he arrived at the conclusion that ‘blood gives no analysis excepting that of common animal matter.’ Principles of Surgery, chap. iii. in Hunter's Works, vol. i. p. 229.
[869] ‘In seeking to determine the respective importance of the different constituents of the blood, by the philosophical and most difficult inquiry into their respective periods of formation in the development of the embryo, Hunter made the interesting discovery that the vessels of the embryo of a red-blooded animal circulated in the first instance colourless blood, as in the invertebrate animals. ‘The red globules,’ he observes, ‘seemed to be formed later in life than the other two constituents, for we see while the chick is in the egg the heart beating, and it then contains a transparent fluid before any red globules are formed, which fluid we may suppose to be the serum and the lymph.’ I well remember the feelings of surprise with which I listened, while at Paris in 1832, to a memoir read before the Academy of Science, by MM. Delpech and Coste, the object of which was the announcement of the same fact as a novel and important discovery. The statement of the French observers was received with all the consideration which its importance justly merited, without its being suspected that our great physiologist had, half a century before, embraced it, with all its legitimate deductions, in the extended circle of his investigations.’ Owen's Preface to vol. iv. of Hunter's Works, p. xiii.
[870] Indeed, if we may rely on the references recently given by Mr. Gulliver, which, from his great general accuracy, there seems no reason to question, the fact that the pale blood precedes the red, was known even in the time of Glisson. See Gulliver's learned edition of Hewson's Works, London, 1846, p. 222. But, to the contemporaries of Glisson, such a fact was isolated, and consequently useless. Nothing is valuable while it appears to stand alone.
[871] ‘From the above account, it appears that whatever may be their utility in the machine, the red globules certainly are not of such universal use as the coagulating lymph, since they are not to be found in all animals, nor so early in those that have them; nor are they pushed into the extreme arteries, where we must suppose the coagulating lymph reaches; neither do they appear to be so readily formed. This being the case, we must conclude them not to be the important part of the blood in contributing to growth, repair, &c. Their use would seem to be connected with strength.’ A Treatise on the Blood, Inflammation, and Gunshot Wounds, in Hunter's Works, vol. iii. p. 68. In another remarkable passage, he touches on the possibility of an increase in the amount of red globules being connected with an increase in the amount of heat. ‘I will not pretend to determine how far this may assist in keeping up the animal heat.’ Observations on the Structure and Œconomy of Whales, in Hunter's Works, vol. iv. p. 364.
[872] The evidence of this is collected in the notes to Buckle's History of Civilization, vol. i. pp. 58–61.
[873] ‘According to Lecanu, temperament has an influence upon the composition of the blood. He infers from his analyses that the blood of lymphatic persons is poorer in solid constituents, and especially in blood corpuscules, than that of persons of sanguineous temperament, while the quantity of albumen is much the same in both.’ Simon's Animal Chemistry with reference to the Physiology and Pathology of Man, London, 1845, vol. i. p. 236. Compare Thomson's Chemistry of Animal Bodies, Edinburgh, 1843, p. 370.
[874] Simon's Animal Chemistry, vol. i. pp. 234, 235. Subsequent experiments have confirmed this. ‘The proportion of red globules dried to 1000 parts of blood, is in healthy males estimated at 127 parts by Andral and Gavarret; lower and higher figures have been given by other analysts, but this probably is the result of somewhat different modes of proceeding. In females the proportion of globules is lower. Becquerel and Rodier make the difference to be about 15 parts per 1000.’ Jones and Sieveking's Pathological Anatomy, London, 1854, p. 23. Hence, the greater specific gravity of male blood. See the interesting results of Dr. Davy's experiments in Davy's Physiological and Anatomical Researches, London, 1839, vol. ii. p. 32.
[875] Hunter died in 1793. The researches of Lecanu were published in 1831.