This Disorder, for the most part, takes its Rise[89] from Calculi lodged in the biliary Ducts[90]; and sometimes from a viscid Mucus or Pituita obstructing those Passages[91]; and it may be brought on by a Tumour, or any other Cause[92], compressing these Ducts, so as to prevent the free Flow of the Bile into the Cavity of the Intestines. [89] Obstructions and Scirrhi of the Liver have been assigned as the Cause of the Jaundice; but as we have so many Cases of this Kind related where no Jaundice appeared, it is now much doubted, whether such Obstructions, which do not affect the Ducts, are capable of producing this Disorder. [90] We have numerous Cases in _Bonetus_, and other physical Observations, where Calculi have been found in the Gall Bladder, and Ducts of People who have died of the Jaundice; and I have frequently found two, three, and sometimes twelve, fifteen, or twenty, such bilious Calculi in these Cavities. [91] Viscid Mucus or Pituita, or viscid Bile, has been observed frequently to obstruct the Ducts. Dr. _Coe_ says, sometimes icteric Patients discharge very thick Bile, almost as viscid as Bird-Lime. See his _Treatise on biliary Concretions_, chap. ii. where he has collected a great Number of icteric Cases, in which the Bile has been found quite viscid after Death. [92] See the Case of a Jaundice in _Bonetus’s Sepulchretum Anatomicum_, tom. II. p. 326, where the Sides of the common biliary Duct were compressed by an Enlargement of the Glands about the _vena portarum_; and we sometimes meet with a Jaundice in pregnant Women which goes off after Delivery, and seems to have been caused by the Pressure of the Uterus and indurated Fœces in the Colon. _Van Swieten_ says, he has seen this very frequently, vol. III. sect. 918, p. 95. The yellow Colour, or Jaundice, observed in the Ague, and some other bilious Disorders, seems to arise sometimes from Spasms of the Ducts; or from too great a Quantity of Bile secreted and absorbed into the Blood, which seems evidently to be the Case where large Quantities of Bile are either vomited or discharged by Stool; a Proof that the biliary Ducts are clear, and free from Obstructions.