A. Pray, Sir, what do you make of the Liver? B. The common Membrane being raised, its Subftance feems to be compofed of finall Glands of a conick Figure, and bound together by a proper Membrane into feveral Heaps or Lobes, which, like Bunches of Grapes, hang to the Branches of the Veffels (viz. the Vena Porta, and the Vena Cava) from which each fmall Gland receives a Twig, and the Lobes are tied to one another by fine Membranes, which fill up the Spaces between them; and thus the parenchymous Subftance of the Liver is formed. A. And, pray, what is its Ufe? B. The Vena Porte brings the Blood to the Liver full of Bile, for its Secretion by the Glands of the Liver; and the Vena Cava carries back the Blood which remains, to the Heart. The Bile thus ftrained from the Blood is, by fmall Veffels, brought to the Gall-bladder, one Part; and the other Part is feparated immediately into the Duct, called the Porus Bilarius; this Duct going out of the Liver, joins the Neck of the Gall-bladder at fome Distance, and forms one common Duct, called the Choledochus, through which both Sorts of Bile mix and pafs to the Lower-end of the duodenum Gut, whereinto it flows in order to mix with the Chyle: Thus the Ufe of the Liver is to feparate the Bile from the Blood. I A. Pray Of the Liver, Spleen, &c. 283 A. Pray what is the Nature and Make of the Spleen? B. The Subftance of the Spleen (contained within two Membranes) is compofed of an infinity of Membranes, which form little Cells and Cavities of different Size and Figure, which communicate with one another, and are always full of Blood. A. Be pleased, Sir, to tell me the Use thereof. B. The Ancients knew nothing of its Ufe; nor can the Moderns do more than conjecture at it. You may fee Dr. Keil's ingenious Hypothefis of its being Nature's Store-house, in which the depofites the arterial Blood for the Ufe of the Liver, in his Anatomy; and the learned Difquifitions of the great Boerhave on this Subject, in his Inftitutions, pag. 139. A. Pray what is that you call the Pancreas? B. It is the fame as is vulgarly called the Sweet-bread; it is called Pancreas from way all; and Kas, Flesh; as much as to fay, a Part all Flesh: It is compofed of an infinite Number of little Glands, it felf being only a large Gland of the conglomerate Kind; whence its Subftance, as we find, is always foft and fupple. A. Pray what is its Ufe? B. To fecern from the Blood brought thither a Liquor called the fancreatick Juice, Juice, which is conveyed by a proper Duct to the duodenum Gut, there to dilute the Chyle. A. Pray what is the Subftance of the Kidneys? B. The Kidneys are likewife two large Glands, whofe parenchymous Substance is composed of an Infinity of very fmall Glands, every where interwoven in the Netlike Inofculations of the fine capillary Branches of their Arteries and Veins: From each fmall Gland proceeds a long fmall Tube; these Tubes approaching towards the Cavity of the Reins, gather together in little Bundles, and form the inner Subftance of each Kidney. A. And, pray, is not their Ufe to feparate the Urine from the Blood? B. Yes; the Blood being conveyed to them by the emulgent Arteries, hath its ferous briny Part ftrained off by their little Glands, and then is returned again by the emulgent Veins; the Urine thus feparated, runs down by the Ureters into the Blad der. 1. Pray what is the Nature and Texture of the Glands? B. The Moderns have reduced all the Glands of the Body to two Sorts, viz. Conglobate Glands, and Conglomerate Glands. A Conglobate Gland is a little fmooth Body wrapped up in a fine Skin, by which it is fepa 285 Of the Kidneys and Glands. feparated from all other Parts, only admitting an Artery to pafs in, and a Vein and excretory Canal, to come out: Of this Nature and Sort, are the Glands of the Brain, of the Lips, and of the Tefticles. A Conglomerate Gland is compofed of many little Conglobate Glands, all tied together and wrapped up in one common Tunicle or Membrane, whofe various excretory Ducts uniting, form one or more larger Pipes, or evacuating Veffels: Of this Sort are the Breafts, the Sweet-bread, the Kidneys, &c. A. Their Ufe I understand is fecretion of Humours from the Blood. B. It is fo: Thus, the Glands of the Brain fecern the Animal Spirits; thofe of the Mouth, the Saliva, or Spittle; thofe of the Breasts, Milk; thofe of the Reias, Urine; those of the Liver, Bile; those of the Tefticles, the generative Semen; and thofe of the Skin, the infenfible Matter of Perfpiration, or Sweat. The Number of thefe fmall cuticular Glands is fomewhat wonderful, it is fuppofed, that one Grain of Sand will cover no less than 125000 of them; if then we reckon only 2000 of these Grains to an Inch Square, and allow at a Medium the Surface of a Man's Body to be equal to 14 fquare Feet; then there will be of those small Glands in the Skin, the Number 324000000000; each of which con tains tain a Pore, or invifible Spiracle, through which we conftantly perfpire. A. Pray what Quantity of Matter goes off by this infenfible Perspiration? B. Sanctorius tells us, in his Aphorifms, that by weighing himself he has found, 1. That a Man fleeping perfpires twice as much as when awake. 2. That a found Man in one Night of feven Hours Sleep, generally perfpires 50 Ounces, or 3 Pounds Averdupoife, or 4 Pounds Troy Weight. 3. That fcarce half a Pound of this per fpires in the first 5 Hours. And we cannot wonder hereat, fince it appears there are above three hundred thousand Millions of Pores in the Body of a middle fized Man through which there muft of Neceffity go off a much greater Quantity than either by Stool or Urine, or both together. A. Well, I am wonderfully pleased to know this furprizing Part of Philofophy, and do intend for the Sake hereof to buy Sanctorius's Book: But, to go on, pray what is the Nature and Use of the Inteftines? B. The Intestines are a long and large Pipe, which by feveral Circumvolutions and Turnings, reaches from the Pylorus of the Stomach to the Anus: They are knit all along to the Edge of a Membrane, called the Mesentery, and are 6 Times as long as |