[f. next: see -ITY. Cf. Fr. excitabilité.]
1. The quality of being excitable, liability or tendency to excitement; in pl. excitable feelings.
a. 1803. Foster, in Life & Corr. (1846), I. 187. Excitement is excitability too.
1840. Carlyle, Heroes (1858), 250. I fancy, the rigorous earnest man, with his keen excitabilities, was not altogether easy to make happy.
1863. Geo. Eliot, Romola, III. 60. Romola … shrank … from the shrill excitability of those illuminated women.
2. Phys. Of an animal or vegetable organ or tissue: The capacity of being excited to its characteristic activity by the action of a specific stimulus. (In the Brunonian physiology excitability or incitability was regarded as the essential principle of vitality; the earlier quots. refer more or less to this theory.)
1788. J. Brown, trans. Elem. Med., § 14. The property, by which both sets of powers act, should be named Excitability; and the powers themselves Exciting Powers.
1799. E. Darwin, Phytol., XIV. i. i. 316–7. The buds of vegetables … possess irritability, and sensibility, and voluntarity, and have associations of motion…. But … the three latter kinds of excitability are possessed in a much less degree by vegetable buds.
1802. Med. Jrnl., VIII. 333. Opium acts primarily on the living principle, or, as he terms it, excitability of the system.
1807. J. E. Smith, Phys. Bot., 65. In forced plants the irritability, or … excitability, is exhausted.
1825. Coleridge, Aids Refl. (1848), I. 34. Pleasure … consists in the harmony between the specific excitability of a living creature, and the exciting causes correspondent thereto.
1854. Bushnan, in Circ. Sc. (c. 1865), II. 3/1. The chemical laws are brought into operation by the agency of an organic excitability.
1866. Huxley, Physiol., ix. (1872), 220. The excitability of the retina is readily exhausted.
