A lecture delivered in King's College, London, on Tuesday, the 11th of October, 1831, being introductory to the first botanical course of the session opening the institution / by Gilbert T. Burnett.

  • Burnett, Gilbert T. (Gilbert Thomas), 1800-1835.
Date:
1832
Catalogue details

Licence: Public Domain Mark

Credit: A lecture delivered in King's College, London, on Tuesday, the 11th of October, 1831, being introductory to the first botanical course of the session opening the institution / by Gilbert T. Burnett. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    one of the most curious physical forces which have been dis- covered in modern times, and the just value of which we have not at present the means of estimating. The same observations apply, and perhaps with still more truth, to that most curious discovery lately made by the ce- lebrated Mr. Robert Brown, who has shewn, by an un- exceptionable series of experiments, that locomotion, even when apparently independent of external forces, may and does exist among particles that are absolutely lifeless; nay, which have never been alive: so that, should not this pheno- menon admit some more probable solution, it would seem that the long-established definition, which declares matter to be inert, may perhaps require a serious modification. This apparently independent motion of the molecules of matter may appear to some to be a close approximation to the vital motions of plants, or the spontaneous movements of animals; and, indeed, the idea would seem more plausible than the belief of some German philosophers, that crystallization is an effect of vitality. The facts are simply these: that grains of pollen, particles of dead plants, some of which have been in herbaria for upwards of a century, nay, even frag- ments of pounded glass and stone, when diffused through water, and viewed with a good microscope, are seen to be in a constant state of motion; and this independent of any eva- poration of, or currents in, the fluid. Furthermore, that they still maintain their restless activity when hermetically sealed between two plates of glass, so as to exclude, as far as pos- sible, all external agitation; and are found, even under such circumstances, to continue their motions unremittingly during an indefinite period; nay, even after the lapse of months, (I believe we may now say years,) to be as full of motion as when first observed. This discovery, as just now hinted, has been thought by some to militate against the ancient dogma, which enunciates the inertia of matter. It would ill become me to advance any speculations other than as mere hypotheses, and this the more especially as the discoverer himself, with that modesty which always attends true genius, does not even venture an explanation: I, therefore, scarcely dare to suggest that it would be desirable to ascertain whether these movements may not be indicators of external motions, so slight as to be imperceptible to other means, rather than as inhei-ent in the particles themselves. Just as many atmospheric changes are notorious with the water, that are utterly inappreciable with the mercurial barometer; and as the expansions of bodies by