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berty, and a more commodious action than it would otherwise have been capable of exerting”. There is nothing, I believe, in a silk or cotton mill, in the belts, or straps, or ropes, by which, motion is communicated from one part of the machine to another, that is more artificial, or more evidently so, than this perforation. III. The next circumstance which I shall mention, under this head of muscular arrangement, is so decisive a mark of intention, that it always appeared to me to supersede, in some measure, the necessity of seeking for any other observation upon the subject: and that circumstance is, the tendons, which pass from the leg to the foot, being bound down by a ligament at the ancle. The foot is placed at a considerable angle with the leg. It is manifest, therefore, that flexible strings, passing along the interior of the angle, if left to themselves, 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 above 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
* Ches, Anat, p, 119.
simplicity, yet the clearness of this contriv-
Keill has reckoned up, in the human body, four hundred and forty-six muscles, dissect- L
ible and describable; and hath assigned a use to every one of the number. This cannot be all imagination. Bishop Wilkins hath observed from Galen, that there are, at least, ten several qualifications to be attended to in each particular muscle; viz. its proper figure; its just magnitude; its fulcrum; its point of action, supposing the figure to be fixed; its collocation, with respect to its two ends, the upper and the lower; the place; the position of the whole muscle; the introduction into it of nerves, arteries, veins. How are things, including so many adjustments, to be made; or, when made, how are they to be put together, without intelligence? I have sometimes wondered, why we are not struck with mechanism in animal bodies, as readily and as strongly as we are struck with it, at first sight, in a watch or a mill. One reason of the difference may be, that animal bodies are, in a great measure, made up of soft, flabby, substances, such as muscles and membranes; whereas we have been accustomed to trace mechanism in sharp lines, in the configuration of hard materials, in the moulding, chiseling, and filing into shapes, of such articles as metals or wood. There is something therefore of habit in the case; but
it is sufficiently evident, that there can be no proper reason for any distinction of the sort. Mechanism may be displayed in the one kind of substance, as well as in the other. Although the few instances we have selected, even as they stand in our description, are nothing short perhaps of logical proofs of design, yet it must not be forgotten, that, in every part of anatomy, description is a poor substitute for inspection. It is well said by an able anatomist”, and said in reference to the very part of the subject which we have been treating of:-"Imperfecta haec musculorum descriptio, non minus arida est legentibus, quam inspectantibus fuerit jucundaeorundem preparatio. Elegantissima enim mechanices artificia, creberrimè in illis obvia, verbis nonnisi obscuré exprimuntur: carnium autem ductu, tendinum colore, insertionum proportione, et trochlearium distributione, oculis exposita, omnem superant admirationem.”
CHAPTER X. t
QF THE WESSELS OF ANIMAL BODIES,
THE circulation of the blood, through the bodies of men and quadrupeds, and the appara* Steno, in Blas. Anat. Animal. p. 2. c. 4.
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tus by which it is carried on, compose a system, and testify a contrivance, perhaps the best understood of any part of the animal frame. The lymphatic system, or the nervous system, may be more subtile and intricate; nay, it is possible that in their structure they may be even more artificial than the sanguiferous; but we do not know so much about them. - The utility of the circulation of the blood, I assume as an acknowledged point. One grand purpose is plainly answered by it; the distributing to every part, every extremity, every nook and corner, of the body, the nourishment which is received into it by one aperture. What enters at the mouth, finds its way to the fingers' ends. A more difficult mechanical problem could hardly I think be proposed, than to discover a method of constantly repairing the waste, and of supplying an accession of substance to every part, of a complicated machine, at the same time. This system presents itself under two views: first, the disposition of the blood-vessels, i. e. the laying of the pipes; and, Secondly, the construction of the engine at the centre, viz. the heart, for driving the blood through them. I. The disposition of the blood-vessels, as