The senses, their division and work : viewed physically and evolutionally / by Henry Muirhead.
- Muirhead, Henry.
- Date:
- [1877]
Licence: Public Domain Mark
Credit: The senses, their division and work : viewed physically and evolutionally / by Henry Muirhead. Source: Wellcome Collection.
Provider: This material has been provided by King’s College London. The original may be consulted at King’s College London.
13/18 page 330
![operations. The fact is, we do not become conscious of one in a hundred of our sensal telegraphic messages. Only of those to 1 which we elect to (1), or are compelled toj devote brain-work do we become conscious,* and even then, the brain-work must be strong enough, and long enough continued-—must have sufficient intensity and sufficient repetition, f so as- to invest the brain with mnemonic j ability to re-enact the mental operation, ere we can become con- i scious of it one instant after, or any other succeeding instant. We j are virtually unconscious of what is merely instantaneous brain- 1 work. When the four cups of a Robison-anemometer revolve with ; great rapidity, we observe one- at the right side and one at the left 1 side, but nowhere between. This is in consequence of the cups 1 remaining longer in the same line of sight at the sides. A Crookes’ r| radiometer shews this easily. [Experiment shewn.] It is by • taking advantage of this fact (as well as distracting our attention) j that the juggler exhibits and performs before our eyes, things and processes of which we fail to become conscious—fail in consequence j of the short-lived brain reaction never acting so again. It appears, .1 therefore, that we are conscious only of what our brain can and does re-enact—that is, of what it can remember, and only during the j * Moreover, it sometimes happens that we do not become conscious of an object j (do not notice and group its constituents) until the external reality ceases to have communication with the sensal nerve ends. For instance, in gazing j intently through a window, some paces off, at a beautiful white cloud, we may fail to note the sash-bars, fail to be conscious of them, until we happen to shut our eyes, and further darken them by a handkerchief; when the window-bars then exhibit themselves quite distinctly in normal distauee, size, and form, but in any direction towards which we turn our eyes. This occurs, we may suppose, in consequence of the affected nerve-ends continuing to quiver in the fashion induced by the reflected light from the bars for a few moments previous to our darkening our eyes. We being still stirred by their telegrams, note the latter, now that the intenser telegrams from the cloud do not distract our attention, note them whilst they are induced by the protracted quiverings of the nerve- ends, and group their intimations in their proper relative positions, according to methods and laws for w'hich we have acquired proclivities and aptitudes through inheritance or long habituation personally. + Of course intensifying and repeating are here understood in synchronous as well as sequent order. If bodies be too minute, their qualities, i.e., their molecular doings, are not able to stir to appreciable feeling reaction until a sufficient number of telegram exciting motants co-operate synchronously or sequently. Diligent practice, however, generates ability to discriminate better— to react consciously to the stimuli of more minute or fewer grouplets than was possible on first attempts; demonstrating that conscious noting and grouping of feelings are organic operations—are, in fact, analogous to what we call more or less artistic work, physical or mental.](https://iiif.wellcomecollection.org/image/b24761916_0016.jp2/full/800%2C/0/default.jpg)
