Berzelius is not disposed to regard the peculiar matter, which is considered to be resin, as strictly falling under that denomination. He says it is precipi-table by acids; and the precipitate is a compound of the acid employed with the green colouring matter of bile. This characteristic ingredient he calls biliary matter. He finds bile composed of:

One circumstance, adds M. Berzelius, relating to this, biliary matter, has much surprised me, which is, that it. gives no ammonia by destructive distillation; therefore . it contains no azote: but what can have become of the azote of the albuminous matter of the blood? for no vestige of it is found in any other of the constituent parts of the bile, nor does bile contain any ammonia.

52. M. Thenard also analyzed human bile; and he is of opinion that his experiments have led him to as accurate a knowledge of it as of any other species. All the acids decompose it, and precipitate from it a large quantity of albumen and resin. These may be separated from each other by alcohol. By the application of acetate of lead no picromel can be discovered; nor is any other ingredient found in human bile than yellow matter, albumen, resin, and salts. The proportions are the following: -

53. The yellow matter appears to be in every respect, similar to that of ox-bile. The resin is yellowish; very fusible; bitter, but less so than that of ox-bile; soluble in alcohol, from which it is precipitated by water; and soluble in alkalies, from which it is thrown down by acids. In water it appears scarcely to dissolve; and yet sulphuric and nitric acids occasion a precipitate from water which has been digested on it.

54. The pancreas, vulgarly called the sweetbread, is a large gland of the salivary kind, lying across the upper and back part of the abdomen, near the duodenum, behind the stomach and between the liver and spleen.

Its length is eight or nine inches, its breadth is about two fingers and a half, and its thickness about one finger: it generally weighs about three ounces. It is composed of innumerable small glands, the excretory ducts of which unite, and form the pancreatic duct; which, in the human subject, always enters the duodenum with the ductus communis choledochus. Although the granulous structure of the pancreas has induced anatomists to regard it as a salivary gland, yet M. Ma-jendie observes, that it differs in the smallness of the arteries which supply it, as well as in not appearing to receive any cerebral nerve. The peculiar fluid it secretes is, doubtless, necessary to digestion, but we are totally ignorant of the particular duty assigned to it. As we descend in the scale of animals, the pancreas disappears: it is found in the shark and skate, but in other fishes its place is supplied by cecal appendices, which afford a copious secretion analogous to the pancreatic liquor. The quantity of fluid prepared by this gland does not appear to bear a just proportion to its size.

Dr. Fordyce first attempted to collect a quantity of it, by inserting a small quill into its duct, in a living dog; when there flowed out a colourless fluid, almost watery, having a saltish taste; and on letting it evaporate on a plate of glass, he observed crystals of common salt, and muriate of ammonia, together with a colourless mucilage. This experiment, however, as its author candidly confesses, cannot be considered as satisfactory, since the secretion did not take place in its natural state; the quill might stimulate the duct, and produce a different fluid. M. Majendie employed a simpler mode: he laid bare the orifice of the canal in a dog, wiped the surrounding mucous membrane with a very fine cloth, and then waited until a drop of liquid passed out; as soon as it appeared, he sucked it up with a capillary tube; and in this manner he succeeded in collecting some drops, but never enough to analyze it with any precision: he recognized in it a slightly yellow colour, a salt taste, but no odour; and he found that it was alkaline, and partly coagulable by heat. The circumstance, says this able experimentalist, which most struck me, was the smallness of its quantity; a drop scarcely passed out in half an hour, and I have sometimes waited longer for it.

That the pancreatic fluid plays an important part in the elaboration of chyle, appears evident from the fact, that diseases of that viscus are attended with extreme emaciation.