Arcana microcosmi, or, The hid secrets of man's body discovered in an anatomical duel between Aristotle and Galen concerning the parts thereof : as also, by a discovery of the strange and marveilous diseases, symptomes & accidents of man's body : with a refutation of Doctor Brown's Vulgar errors, the Lord Bacon's natural history, and Doctor Harvy's book, De generatione, Comenius, and others : whereto is annexed a letter from Doctor Pr. to the author, and his answer thereto, touching Doctor Harvy's book De Generatione / by A.R.

CHAP. VII.

1. How the spirits pass through the nerves: their swift and various motions, even in sleep: motion and sense not still together. 2. Sense and motion in phrensies, epilepsies, leprosies, caros. 3. Muscles, how, when and where the causes of voluntary motion. 4. How the fibres and tendons move the muscles. 5. The muscles of the tongue, abdomen, diaphragma, ribs, bladder. 6. The organs of tact, its medium.

I. ALTHOUGH the nerves are not sensibly pervious as the Veines and Arteries are, which were purposely made hollow for the passage of the venal and arterial blood; yet the animall spirits being subtil and sublimated bodies can free∣ly passe through the soft and spungy substance thereof, as wel as sweat through the pores of the skin. 2. Though in the Palsie the animal spirits cannot passe through the thick, clam∣my and glassy flegme, which by reson of its coldnesse, deads the spirits, which without the natural heat, have no vigour or motion, yet they can freely passe through the nerves by help of the native heat. 3. Though the spirits by reason of their specifical form or aeri••l nature should only move upward, yet as they are instruments of the soul, they move which way the soul will have them move. 4. Though no grosse body can move in an instant, yet their spirits can, being moved by the soul immediatly, and being such sublimate and subtil bodies, that they come neer to the nature of spirits. 5. Though in sleep the senses are tied up, yet there is ofte••∣times motion; as we see in those that walk and talk in their sleep, and yet feel not; because the fore ventricles of the brain are affected, in which is the common sense, so is not the pith in the back, from which the most of the motory nerves have their original. 6. In one and the same nerve oft¦times motion faileth, and the sense remaineth, because more spi∣rits are required, and greater force for motion being an acti∣on, then for sense, which consisteth in reception or passion. 7. Sense doth sometimes fail, the motion remaining sound; when the nervous branches which are inserted into the skin, are hurt or ill-affected, at the same time the nerves inserted in∣to the muscles may be sound.

II. In phrensies the motion is strong, but the sense weak; because the braines being inflamed, the nerves are heated

and dried, therefore fitter for motion, but the lesse apt for sense, which requireth a soft nerve. 2. In the falling sickness sense faileth, but not motion, because the fore ventricles of the brain being ill-affected, the common sense is intercepted; but the pith of the back bone from whence the most nerves are de∣rived, is not hurt, therefore motion not hindred. 3. In lepro∣sies the sense is dulled, but not the motion, because the nerves and skin are dried, by which sense is hindred, but not motion. 4. In a deep sleep or Caros, there is respiration without sense, because the fore-part of the brain is hurt, but not the nerves and muscles of the breast. 5. Oftentimes the eye lo∣seth its sight, but not its motion, because the optick nerve by which we see, is not the same with the nerves, by which the eye is moved.

III. All spontaneous motions are caused by the spirits in the brains, nerves and muscles in the creatures that have them, but where these organs are not, the animal spirits move the body without them, as we see in worms. 2. All muscles are not the organs of voluntary motion: for the three little muscles with∣in the ears move them not to hear when we please, for many times wee hear what wee would not. 3. In those parts where there be nerves without muscles, there is no voluntary moti∣on, because the nerves convey only the spirits, which the mu∣scles receive, and by them immediately move the body. 4. Re∣spiration in sleep is a natural, not a voluntary motion, caused notwithstanding by the muscles of the breast. 5. Sleep-walk∣ers are moved by the muscles, which motion then cannot be vo∣luntary, for the walker hath not knowledge of his walking, or of the end thereof. 6. Beasts are moved by their muscles, which motion in them cannot be called voluntary, but sponta∣neous onely.

IV. All muscles have not tendones, but such as are appoint∣ed for a strong and continual motion: hence the muscles of the tongue, bladder, and anus, have no tendones. 2. The muscle is moved not onely by the nerves and tendones, but also by the fibres within its own fleshy substance: and indeed the fibrous flesh is the chief instrument of spontaneous moti∣on; and where they are wanting, there is no such motion: Hence it is that beasts can move their skins, which men can∣not, because beasts skins adhere close to a fibrous substance, whereas that of mans is nervous; onely the skin of the face in us is movable, because musculous and fibrous.

V. Though the substance of the tongue be not a musculous

or fibrous flesh, yet it receiveth its divers motions from divers muscles. 2. The muscles of the abdomen are chiefly made for pressing of the same, when nature desires to expel the ex∣crements, and in the next place to move the breast with the other muscles appointed for respiration. 3. The muscle of the bladder called Sphincter, was made partly for opening a passage for the urine to passe away, which it doth by dilating and extending it self; and partly for shutting up of the blad∣der by contracting it self, lest the urine should passe from us in sleep, or against our wills whilest we are awaked. 4. The muscle called diaphragma, or the midriff, was made for ex∣spiration and inspiration; in inspiration, it dilateth it self, but in expiration, it is contracted upward, as we see in dead bodies. 6. The muscles of the ribs called Intercostals, are some of them external, which distend the breast for inspiration, some inter∣nal, which contract the breast for exspiration.

VI. Aristotelians will have the flesh, Galenists the skin to be the organ of tact: but I think both are; for I take the skin to be nothing else but the outward superficies of the flesh, a lit∣tle dried and hardned; and differing no other way from the flesh, then the outward skin of the apple, from the softer sub∣stance thereof; so then the flesh, both as it is a soft substance, and as it is hardned in its outward superficies, is the organ of tact, by means of the nerves and fibres diffused into it; and whereas vision, hearing, and smelling, have the air for their medium, tact and taste, which are the two absolutely need∣full senses, without which we cannot live, (whereas with∣out the other three we may) have no medium at all.