Nine books of physick and chirurgery written by that great and learned physitian, Dr Sennertus. The first five being his Institutions of the whole body of physick: the other four of fevers and agues: with their differences, signs, and cures.

CHAP. XII. Of the Animal Faculty, and first of the external senses.

THE Third sort of faculties and actions in man, * 1.1 Physitians call Animal faculties, which either are resident in the brain, or de∣rived from it, and takes necessary helps or the p••rformance of its acti∣ons from adjacent parts. They distingui•••• the Aminal faculties, into the sensitive, motive, and Princes, and under the sensitive only the external senses are comprehended; under the Princes, the internal and rational power is involved: we will handle them in this order; first we will treat of the external senses, afterwards of the internal and rational faculties, at last of the appetite and moving faculty. * 1.2

The external senses are those by which we perceive and judge sensible external objects, without the precedence of any other facul∣ty. But that a perception may be made four things ought to con∣cur, first the mind perceiving, secondly the instrument which is double; first the Spirit, secondly the member, whe••ein the sense is; thirdly the object or perceptible things, fourthly the medium inter∣ceding betwixt the instrument and the object.

The external s••nses are five, Seeing, Hearing, Smelling, Tasting, * 1.3 Touching or Feeling.

The Sight is an external sense, discerning and knowing by the benefit of the Eye, the several kinds of visible things; whose adae∣quate Instrument is the Eye; the Eye consists of divers Tunicles, the adnate or conjunctive, the Horny, the Grapy, in the middle whereof is a round hole, which is called the Pupil, and is the inlet

and window as it were of visible Species; then the Tunicle in man∣ner of a Net, the Pannicle without a name, the Cobweblike and the Vitreous Membranes; three humors, the watery, Crystalline, and Vitreous; a nerve optick and muscles. The object of sight is what∣ever is visible, to wit, colours, which are visible in potentia, in that they are capable of being seen, but in action to be visible light is required. The medium is any transparent and diaphanous body.

Hearing is an external sense, * 1.4 perceiving by the benefit of the eare any sound that is audible; the adaequate instrument, or that without which a sound cannot be heard is the Eare, but especially as Galen teacheth in his first Book and third Chapter, of the causes of Symptomes, the term and exrremities of the Auditory Pores, where the end being dilated, the Auditory Nerves receive part of the sound. The Object is whatever is audible, or sound: the medium which it is conveyed through, is water and aire.

Smelling is an external sense discovering smells by the benefit of the Nose, * 1.5 or mammillary processes. Its adaequate instrument are the Nostrils, but principally the mammillary processes; Its object odours, the medium by which odours are conveyed, is aire, and water.

Tast is an external sense, * 1.6 perceiving savours by help of the tongue; Its proper Instrument is the Tongue, a thin flesh soft and spungy, like to no other part of the body; the Object is savours, the medium a spongy skin, or porous cover of the Tongue, and spitly moisture.

Touch lastly is an external sense, * 1.7 discovering by the benefit of a membrane all Tangible bodies. But though the skin be the chiefest instrument of the sense of feeling, and covereth the whole body, that it may descry external objects and injuries happening to the body, and the skin in the hand be the chiefest rule to try all tangibles: yet there is no adaequate Instrument of touch; since it is more largely diffused, and other parts are likewise indued with that sense. But the adaequate organ that is of touch is a membrane; For wheresoever a membrane is there may be a touch, and where∣soever a membrane is not, there cannot be a touch, and the skin it self obtains that whereby it is sensible, as it participates of the fibers and little membranes of the Nerves.

Notes

• * 1.1

  The Ani∣mal facul∣ty.
• * 1.2

  The exter∣nal senses are five.
• * 1.3

  The five external senses. Seeing.
• * 1.4

  Hearing.
• * 1.5

  Smelling.
• * 1.6

  Tasting.
• * 1.7

  Feeling.