The muscular system would afford us numerous examples of what may be call ed mechanical structure : e. of such contrivances, employ-ed to attain certain objects, as a human artist would adopt on similar occasions. One of the muscles of the eye-ball presents us with a wry per fect pulley ; by- means of which the globe of the ey-e is moved in a direction exactly contrary to the original application of the force. This muscle, which is called the trochlearis, arises from. the very back part of the orbit : it has a long and slen der tendon, running through a pulley in the inner part of the front margin of the orbit, and then going back to be fixed the hind portion of the eye-ball. Thus it draws the globe obliquely upwards and forwards, although the line of•the con traction of the muscle is directly back ward.
In the toes and fingers, the long ten don, which bends the first joint, pa.sses through the short tendon, whiclt bends the second joint.
, The foot is placed at a considerable angle with the leg. It is manifest, there fore, that flexible strings, passing along the interior of the angle, if left to them selves, would, when stretched, start from it. The obvious preventive is to tie them down, and this is done in fact. Across the instep, or rather just abote it, the anatomist finds a strong ligament, under which the tendons pass to the foot. The effect of the ligament, as a bandage, can be made evident to the senses ; for if it be cut, the tendons start up. The sim plicity, yet the clearness of this contri vance, its exact resemblance to establish . ecl resources of art, place it among the most indubitable manifestations of design with which we are acquainted.
The number of the muscles of the human body is so great, and the circum stances which demand attention in every muscle are likewise so numerous, that a particular description of each would ex tend this article beyond its prescribed limits. We shall therefore merely give a catalogue of the muscles ; which, toge ther with the references to the annexed plates, will give the reador a sufficiently clear notion of the subject.
Miracles of the scalp.-1.Fronto-occipita lis, or epicranius.
Muscles of the Attollens auricu lam ; 2. anterior auris ; 3, 4. retrahentes auricillam ; 5. major helicis ; 6. minor he licis 7. tragicus ; 8. antitragicits; 9. transversus anriculx ; 10. laxator tym pani major ; 11. laxator tympani minor; 12. tensor tympani ; 13. stapedeus.
Mitsclecs of the eye.-1. Orbicularis pal pebrarom ; 2. corrugator supercilii; 3. levator palpebrx superioris; 4. attollens oculi ; 5. abductor oculi ; 6. depressor 7. adductor oculi: these are also called rdcti r adz. rectus superior, exter nus, inferior, and internus ; 8. obliquus superior oculi, or trochlearis ; 9. obliquus inferior oculi.
Miracles of the nose.-1. Compressor na rium ; 2.levator labii superioris et alx na si ; 3. nasalis labii superioris ; 4. depres sor six nasi.
Muscles of the lips.-1. Levator labii su perioris; 2. zygomaticus major ; 3. zygo maticus minor ; 4. levator anguli oris ; 5. depressor anguli oris ; 6. depressor labii inferioris; 7. buccinator ; 8. orbicularis oris ; 9. anomalus maxillx superioris ; 10. levator menti.
Lerwerjaw.-1. Biventcr maxillx, or di gastricus ; 2. masseter ; 3. temporalis; 4. pterygoideus externus; 5. pterygoideus internus.
Xerk.-1. Latissimus colli, or platysma myoides ; 2. sterno-cleido-mastoideus.
Tongue and thyroid cartilage.-1. Omo hyoideus; 2. sternohyoideus ; 3. sterno thyreoideus ; 4. hyothyreoideus ; 5. mus eums glandulx thyreoidex ; 6. stylohy oideus ; 7. styloglossus ; 8. mylohyoideus ; 9. geniohyoideus ; 10. hyoglossus; 11. ge nioglossus; 12.1ing-ualis.
Muscles of the pharynx and palate.-1. Stylopharyngeus ; 2. constrictor pharyn gis superior; 3. constrictor medius; 4. constrictor inferior; 5. salpingo-pharyn getts ; 6. palato-pharyngeus ; 7. constric tor 'salmi faucium; 8. levator palatimol lis; 9. circumflexus palati ; 10. azygus uvula.
Miracles of the larynx.-1. Cricothyreoi deus; 2. cnico-arytenoideus posticus ; 3. crico-arytenoideus lateralis; 4. arytenoi deus obliquus; 5. arytenoideus transver ses; 6. thyreo-arytenoideus; 7. thyreo epiglotticus.
The whole number of muscles about the head, neck, and throat, is therefore 72.
Miracles of the abdomen.-1. Obliquus externus abdominis ; 2. obliquus internus abdominis; 3. transversalis abdominis; 4. rectus abdominis; 5. pyramidalis ; 6. dia phragms or septum transvcrsum.
Muscles of the thorax.-1. Sterno costa. lis, or triangularis stern; 2. serratus ticus superior ; 3. scrratus posticus infe rior; 4, 5, 6. scalcnus anterior, medius, and posterior ; 7 to 18. levatorcs brcvio res costarum ; 19 to 21. levatores longi ores costarum; 22. intercostales externi ; 23. intercostales intern; 24. quadratus lumborum.