tions. These means, however, are not wanting; the jaws are capable of six different movements, upwards and downwards, forwards and backwards, right and left, by means of muscles attached to them for that purpose; some of them working in a very curious way, and several acting in every motion of the jaws. By the movements of which the tongue is capable, the food is placed in different positions, to facilitate the process of mastication. But moisture is necessary; and moisture is provided. About the jaws and tongue there are many glands placed, the office of which is to secrete a fluid; by the action of chewing, this moisture exudes, and, mixing with the food, assists the working of the jaws and tongue, in bringing it into a condition fit for the stomach. Now, I ask, whether there is any mill for grinding corn, or malt, or any other substance, that is constructed with an ingenuity equal to that which the apparatus of the mouth displays in this process? And if we admit intelligence, acting with reference to an end in the less, by what rule of reasoning ought we to exclude it from the greater?

The apparatus for conveying the food to the stomach is not less appropriate and ingenious. The mechanism of the many muscles employed, the elasticity of the tube, called the esophagus, through which it passes, the lubricated state in which this tube is kept by a liquid secreted for that purpose, and its action in forcing the food towards its destined receptacle, are all most curious processes, on which we cannot stop to particularize. We must, however, notice one instance of most exquisite contrivance. At the lower and back part of the head,

behind the tongue, is a funnel-shaped bag, called the pharynx, the wide part opening towards the mouth, the pipe being the esophagus, which leads down into the stomach. Into the upper and anterior portion of this bag, two holes open, by which the air passes from the nostrils, through another tube called the trachea, or windpipe, into the lungs. Into the same bag the food also enters, in order to pass by the esophagus into the stomach. But, as the trachea is placed in front of the æsophagus, is there not great danger of the food passing into the lungs, and fatally obstructing their important function? This danger was evidently foreseen and obviated. In the very act of swallowing, a cartilaginous valve, called the epiglottis, closes the aperture of the windpipe securely, so that the food passes easily and safely into the passage which conveys it to the stomach. But for this valve, death would be certain, either through inanition, if, aware of the danger, we abstained from food, or by instant suffocation, if we attempted to swallow. Without this valve, the new-born infant would perish at its mother's breast;-without this valve, the first morsel that the first man endeavored to swallow, would have terminated at once his being and his race. Has any contrivance, resulting from foresight and human intelligence, ever exhibited precaution with more distinctness and effect? Who can forbear exclaiming with devout admiration, "the finger of God is here."

By the act of deglutition, the food so far prepared is conveyed through the esophagus into the stomach. Here it undergoes another important process. Besides

the muscular action, to which every part of the solid food taken into the stomach is successively exposed, by being brought into contact with its surface, there is in this organ a fluid secreted, of a most peculiar nature, which from its situation is called the gastric juice. This, it is found by experiments, is, in different animals, adapted to the kind of food on which they respectively live, -whether vegetable or animal, or both. No chemistry can form any thing like this extraordinary liquid. It is apparently the mildest of all fluids; and yet its power as a solvent is unequalled. In the human stomach it acts on vegetable and animal matter deprived of vitality, in a manner which is truly astonishing; and yet, on the living fibre, and, consequently, on the coats of the stomach, which, during life, contains it, it has no power. Did a chemist ever contrive a solvent with more evident adaptation to the substance to which it should be applied, and at the same time with a nicer adjustment, so that it should accomplish no incidental mischief, but effect the intended good, and that alone? The food is thus converted into a pulpy liquid, called chyme. But the necessary process is not completed; the substance, thus far prepared, has to pass into a kind of second stomach, called the duodenum, the entrance to which is termed the pylorus. "Nothing in the animal economy is more curious and wonderful, than the action of that class of organs of which the pylorus affords a remarkable example. If a portion of undigested food presents itself at this door of the stomach, it is not only not permitted to pass, but the door is closed against it with additional firmness; or, in other words, the muscular

fibres of the pylorus, instead of relaxing, contract with more than ordinary force. In certain cases, or where the digestion is morbidly slow, or when very indigestible food has been taken, the mass is carried to the pylorus before it has been duly acted on by the gastric juice; then, instead of inducing the pylorus to relax, in order to allow of its transmission to the duodenum, it causes it to contract with so much violence as to produce pain, while the food thus retained in the stomach longer than natural, disorders the organ; and if the digestion cannot ultimately be performed, that disorder goes on increasing until vomiting is excited, by which means the load that oppressed it is expelled. The py lorus is a guardian placed between the first and the second stomach, in order to prevent any substance from passing from the former until it is in a condition to be acted on by the latter; and so faithfully does this guardian perform its office, that it will often, as we have seen, force the stomach to reject the offending matter by vomiting, rather than allow it to pass in an unfit state; whereas, when chyme, duly prepared, presents itself, it readily opens a passage for it into the duodenum.”* How serious would have been the mischief resulting to the whole frame, if some such expedient had not prevented the too early transference of the contents of the stomach to its next stage? On this our health and strength in a great measure depend. And can it be believed, that so necessary and beneficial an arrangement is the result of accident and undesigning necessi

* Library of Useful Knowledge.-ANIMAL PHYSIOLOGY, p.41.

ty? Is not the wisdom that built the human frame apparent here?

But the process goes on; and as the substance now called chyme moves forward, it receives other changes from peculiar fluids, secreted just in the proper place, and applied just at the proper time; the principal of which appears to be the bile, prepared by the liver, and exuded by a duct, so as to mix with the chyme in the duodenum. Another change is the consequence of this; its purest portions then separate into chyle, a creamlike liquor, which, passing slowly along the intestines, gradually disappears, being absorbed by the lacteals, an innumerable quantity of hair-like vessels, which, uniting, pass, by a circuitous route, into the thoracic duct, the contents of which are poured into a large vein communicating with the heart. The chyle thus mixes with the blood, and is then prepared for circulating through the system. How truly admirable are those processes; how wonderful and complicated the apparatus; how exact all the arrangements by which the food we eat, whether vegetable or animal, seeds or fruits, is converted into that vital fluid which ministers nutrition to the whole system, and supplies its constant waste! What chemical laboratory, with its furnaces, and crucibles, and alembics, all in full action, can give stronger proofs of intelligence and design?

But we must notice, in the next place, though with a far greater attention to brevity than the subject deserves, the manner in which the preparation thus formed is distributed through the system. The whole circulation of the blood depends on the heart. Centrally situated