46 MECHANICAL AND IMMECANICAL PARTS 



no doubtfulness into our observations upon the sequel of 

 the process. Which observations relate, 1st, to the con- 

 stitution of the muscle ; in consequence of which consti- 

 tution, the swelling of the belly or middle part is neces- 

 sarily and mechanically followed by a contraction of the 

 tendons : 2dly, to the number and variety of the muscles, 

 and the corresponding number and variety of useful powers 

 which they supply to the animal ; which is astonishingly 

 crreat; 3dly, to the judicious (if we may be permitted to 

 use that term, in speaking of the author, or of the works, 

 of nature,) to the wise and well-contrived disposition of 

 each muscle for its specific purpose ; for moving the joint 

 this way, and that way, and the other way ; for pulling 

 and drawing the part, to which it is attached, in a determi- 

 nate and particular direction ; which is a mechanical oper- 

 ation, exemplified in a multitude of instances. To mention 

 only one ; the tendon of the trochlear muscle of the eye, 

 to the end that it may draw in the line required, is passed 

 throuLrh a cartilaginous ring, at which it is reverted, exactly 

 in the same manner as a rope in a ship is carried over a 

 block or round a stay, in order to make it pull in the direction 

 which is wanted. [PI. v. fig. L] All this, as we have said^ 

 is mechanical ; and is as accessible to inspection, as capa- 

 ble of bein^ ascertained, as the mechanism of the automa- 

 ton in the Strand. Suppose the automaton to be put in 

 motion by a snagnet (which is probable,) it will supply us 

 with a comparison very apt lor our present pur[)Ose. Of 

 the magnetic effluvium we know perhaps as little as we do 

 of the nervous fluid. But magnetic attraction being as- 

 sumed (it signifies nothing from what cause it proceeds,) 

 we can trace, or there can be pointed out to us, with per- 

 fect clearness and certainty, the mechanism, viz. the steel 

 bars, the wheels^ the joints, the wires, by which the motion 

 so much admired is communicated to the fingers of tiie im- 

 ac/e ; and to make any obscurity, or difli -ulty, or contro- 

 versy in the doctrine of magnetism, an objection to our 

 knowledge or our certainty concerning the contrivance, or 

 the marks of contrivance, displayed in the antomaton, 

 would be exactly the same thing, as it is to make our ig- 

 norance (which we acknowledge) of the cause of nervous 

 agency, or even of the substance and structure of the 

 nerves themselves, a ground of question or susj)icion as to 

 the reasoning which we institute concerning the mechani- 

 cal part of our frame. That an animal is a machine, is a 

 proposition, neither correctly true, nor wholly false. ThQ 



