so slow and awkward, that his father said: "What are you doing? You seem to be half asleep. Pray move as if you were alive."

Observing Harry's reluctance to own his helpless state, Mrs. Beaufoy said: "Harry is very stiff in consequence of his exertion last night; but he does not like to acknowledge that so delightful a game can have any unpleasant consequences."

"Oh, is that all!" said his father: "then we will have another game to-night, and play off the stiffness.' Harry's countenance brightened; for he had been very much afraid that cricket would be prohibited in future, because his mother ascribed his stiffness to that cause, and he began to eat his breakfast with great satisfaction. Presently, however, having occasion to hand his empty cup to his mother, his shoulder gave him so severe a twinge, that he set the cup down hastily, and rising from his chair, made use of his left hand to push the cup across the table. His father observed the action, and smiled, saying, "I see we must put off our game till to-morrow : you will not hit the wicket to-night.'

"Oh, my shoulder is a great deal better since mamma bathed it. I dare say it will be quite well in the evening. But papa, do you really think that playing at cricket can have any more effect on the shoulder than playing at trap-ball ?"

"Not if you played with the same bat; but that which I gave you last night is longer and heavier than your old one: it requires much more

strength to use it, and no doubt, your mother is perfectly right in thinking that this unusual exertion of the muscles has produced the stiffness that incommodes you.".

"The muscles, papa, I do not understand you. I thought this ball-and-socket joint was in fault. Indeed, when I first waked, and found that I could not move my arm, I thought it had slipped out of its place.

Mr. Beaufoy laughed heartily at this, and then said, with mock gravity, "I cannot be surprised at your thinking so, as these slippery joints are 6 so apt' to be out of order. No wonder that your shoulder should be dislocated by turning in your bed."

Harry was not a good judge of probabilities at the moment of waking; especially when he felt a pain he could not account for," said his mother.

“You have an excellent advocate there, behind the tea-urn; but, my dear boy, you must learn to use your reason, and not fancy impossibilities, even though you happen to be just awake."

"You must recollect, my dear," resumed Mrs. Beaufoy," that Harry knows nothing of the mechanism of the shoulder, except its bony construction. If you will be so kind as to explain the powers of the muscles to him, he will be prepared to make use of his reason another time."

Thus called upon, Mr. Beaufoy readily undertook the task proposed, and reminded his son of

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the conversation he had had some days before with his mother; when she had informed him that the nerves, which proceed from the brain and the spinal marrow, are the organs of sensation, and also the means of exciting the muscles to action: thus forming the communication between the mind, or intelligent principle, and the mechanism of the body. Yesterday evening," continued he, your desire to strike the ball was instantly followed by the contraction of certain muscles connecting the arm and shoulder. The power supplied by the nerves distributed on those muscles, occasioned that contraction; and the result of the whole was a quick and forcible motion of intendthe arm, fitted to produce the effect ed. Again, your nerves are now informing your mind, in very intelligible language, that she has imposed too hard a service upon the muscles, and I hope she possesses sufficient prudence to be more reasonable in her requisitions another time."

you

"I thought, papa," said Harry, laughing, "that we were to cure the stiffness by another game at cricket."

"Certainly we must, however, wait till the muscles recover their power of action. But I wish to know whether you understand the communication between mind, nerve, muscle, and limb, which I have been attempting to describe."

'I do not understand how the mind acts upon the nerves, but only that there is some communication between them: then the nerves act upon

the muscles, and the muscles, you say, have the power of moving the limbs. But I do not know what these muscles are, nor whereabouts to look

for them."

"Then I will tell you," replied his father. "The muscles constitute that part of the human body which we call flesh: they are bundles of red fibres. Many of the large muscles consist of two distinct parts; the belly, or swelling part in the centre, and the shining tendons at the ends, by which it is attached to the neighbouring parts. I cannot think of a better example of a muscle, than that which you must often have seen at the knuckle of a leg of mutton."

"I remember it perfectly, papa: it is very good to eat. And I know that the shape of that piece of flesh is just what you describe, swelling and bulging in the centre, and ending in two skinny, shining tendons."

"Since you have a distinct idea of the form of a muscle, I think you may understand how it acts. Muscles possess the power of contracting or shortening themselves in the fleshy, central part: this necessarily draws the tendons at the ends tighter and the tendons, when pulled, occasion motion in the parts attached to them."

:

"I understand that very well," said Harry: "I saw it in the claw of the fowl."

"Then you are the better prepared for what I am going to say. Whatever motion any joint is capable of performing, that motion, the muscles attached to it have the power of producing.

For instance, the joint at the knuckle of a leg or a shoulder of mutton is a hinge-joint.

The mus

cle you remember to have seen lies along the bone, one tendon being attached to the part above the joint, the other to the part below it; therefore, as this muscle is lengthened or contracted, the joint must shut or open; the only motions of which hinge-joints are capable. The same structure is observed in our elbows and knees, which are also hinge-joints, capable of moving only in one direction; and it is a proof of design, that these joints are not furnished with any muscles, but such as are necessary for producing that particular motion."

"But the shoulder is a ball-and-socket joint, papa; how are the motions belonging to it produced?"

"Those motions are provided for by appropriate muscles. I believe our old friend Chambers will enable me to show you one or two of the most remarkable."

Harry ran to fetch the book, and on first looking at the plates representing muscular action, was immediately struck with the resemblance of form between many of the great muscles, and his acquaintance at the knuckle of a leg of mutton. His father then pointed out to him the muscle called Deltoides, in the back view of the shoulder, the point of which it covers like a triangular cap. He told Harry that the use of this muscle is to lift up the bone of the arm, into the middle of which one of its tendinous extremities is insert