of branches; their extremities every where communicating with little round bodies, in the fubftance of which bodies the fecret of the machinery seems to refide, for there the change is made. We can difcern pipes laid from these round bodies towards the pelvis, which is a bafon within the folid of the kidney. We can discern these pipes joining and collecting together into larger pipes; and when fo collected, ending in innumerable papillæ, through which the fecreted fluid is continually oozing into its receptacle. This is all we know of the mechanifm of a gland, even in the cafe in which it feems most capable of being investigated. Yet to pronounce that we know nothing of animal fecretion, or nothing fatisfactorily, and with that concife remark to difmifs the article from our argument, would be to dispose of the subject very hastily and very irrationally. For the purpose which we want, that of evincing intention, we know a great deal. And what we know is this. We fee the blood carried by a pipe, conduit, or duct, to the gland. We fee an organized apparatus, be its conftruction or action what it will, which we call that gland. We fee the blood, or part of the blood, after it has paffed through

through and undergone the action of the gland, coming from it by an emulgent vein or artery, i. e. by another pipe or conduit. And we see alfo, at the fame time, a new and fpecific fluid iffuing from the fame gland by its excretory duct, i. e. by a third pipe or conduit; which new fluid is in fome cafes difcharged out of the body, in more cafes retained within it, and there executing fome important and intelligible office. Now fuppofing, or admitting, that we know nothing of the proper internal constitution of a gland, or of the mode of its acting upon the blood; then our situation is precisely like that of an unmechanical looker-on, who ftands by a stocking-loom, a corn-mill, a carding-machine, or a threshing-machine at work, the fabric and mechanism of which, as well as all that paffes within, is hidden from his fight by the outfide cafe; or, if feen, would be too complicated for his uninformed, uninstructed understanding to comprehend. And what is that fituation? This fpectator, ignorant as he is, fees at one end a material enter the machine, as unground grain the mill, raw cotton the carding-machine, fheaves of unthreshed corn the threshing-machine; and,

when

when he cafts his eye to the other end of the apparatus, he fees the material iffuing from it in a new state; and, what is more, in a state manifeftly adapted to future uses; the grain in meal fit for the making of bread, the wool in rovings ready for fpinning into threads, the fheaf in corn dreffed for the mill. Is it neceffary that this man, in order to be convinced, that defign, that intention, that contrivance has been employed about the machine, fhould be allowed to pull it in pieces; fhould be enabled to examine the parts feparately; explore their action upon one another, or their operation, whether fimultaneous or fucceffive, upon the material which is prefented to them? He may long to do this to gratify his curiofity; he may desire to do it to improve his theoretic knowledge; or he may have a more fubftantial reason for requesting it, if he happen, inftead of a common vifitor, to be a mill-wright by profeffion, or a perfon fometimes called in to repair fuch-like machines when out of order; but, for the purpofe of ascertaining the existence of counfel and defign in the formation of the machine, he wants no fuch intromiffion or privity. What he fees is fufficient. The effect upon the material, the

change

No

change produced in it, the utility of that change for future applications, abundantly testify, be the concealed part of the machine or of its construction what it will, the hand and agency of a contriver. If any confirmation were wanting to the evidence which the animal fecretions afford of defign, it may be derived, as hath been already hinted, from their variety, and from their appropriation to their place and use. They all come from the fame blood; they are all drawn off by glands; yet the produce is very different, and the difference exactly adapted to the work which is to be done, or the end to be answered. account can be given of this without resorting to appointment. Why, for inftance, is the faliva, which is diffused over the feat of tafte, infipid, whilft fo many others of the fecretions, the urine, the tears, and the sweat, are falt? Why does the gland within the ear feparate a viseid fubftance, which defends that paffage; the gland in the upper angle of the eye, a thin brine, which washes the ball? Why is the fynovia of the joints mucilaginous; the bile bitter, ftimulating, and foapy? Why does the juice, which flows into the ftomach, contain powers, which make that bowel,

H

bowel, the great laboratory, as it is by its fituation the recipient, of the materials of future nutrition? These are all fair questions; and no answer can be given to them, but what calls in intelligence and intention.

My object in the prefent chapter has been to teach three things: first, that it is a mistake to suppose, that, in reasoning from the appearances of nature, the imperfection of our knowledge proportionably affects the certainty of our conclufion; for in many cafes it does. not affect it at all: fecondly, that the different parts of the animal frame may be claffed and diftributed, according to the degree of exactnefs with which we can compare them with works of art thirdly, that the mechanical parts of our frame, or, thofe in which this comparison is most complete, although conftituting, probably, the coarseft portions of nature's workmanship, are the propereft to be alledged as proofs and fpecimens of design.

CHAP.