Firstly, IN DISEASES AFFECTING THE LIVER—
(a) Cancer.
(b) Tubercle.
(c) Cirrhosis.
(d) Inflammation.
(e) Atrophy.
(f) Amyloid, and
(g) Fatty degeneration.

Secondly, IN DISEASES OF THE BILE-DUCTS—
(a) Congenital deficiency.
(b) Accidental obstruction. The latter arising from gall-stones, hydatids, foreign bodies (such as cherry-stones and entozoa) entering from the intestines.
(c) Ulcer of the duodenum.
(d) Tumours of the pancreas.

Thirdly, IN AFFECTIONS OF OTHER ORGANS OF THE BODY EXERTING AN INFLUENCE ON THE BILIARY SECRETION—
(a) Diseases of the nervous system.
(b) Diseases of the lungs.
(c) Diseases of the heart.
(d) Imperfect establishment of the extra-uterine circulation (infantile jaundice).
(e) Dyspepsia.
(f) Torpidity of the bowels, and consequent accumulation of fæces in transverse colon.
(g) Pregnancy.

Fourthly, IN A VARIETY OF ZYMOTIC DISEASES—
(a) Typhus.
(b) Yellow fever.
(c) Ague.
(d) Pyæmia.
(e) Epidemic jaundice.

Fifthly, AS A RESULT OF THE INJURIOUS EFFECTS OF CERTAIN POISONS—
(a) Snake bites.
(b) Alcohol.
(c) Chloroform, etc.

Can it be wondered, then, that a state so easily diagnosed is nevertheless so difficult to comprehend?

Notwithstanding the apparent incongruity of the diseases with which the one common symptom of jaundice is associated, I trust to be able to reconcile these discrepancies, and prove that the seeming discord is but "harmony not understood."

All physicians, I think, admit that the peculiar state of the system to which the name of jaundice has been applied, is essentially due to some derangement of the biliary function, the exact nature of the derangement being alone the point of contention. I need not, therefore, waste the time of my readers, either by giving an account of the literature or a detail of the symptoms of jaundice. Even in discussing its pathology, I shall strictly limit myself to the consideration of the opinions at present held by the more advanced of our pathologists; the object of this monograph being, not to pourtray the views of others, but to give a brief exposé of my own, and to point out how modern physiology, and chemistry have not only thrown a new light on its pathology, but have also given us a clue to its successful treatment.

Frerichs, the most recent writer on this subject, in his elaborate treatise on diseases of the liver, says that jaundice may result from one of the three following conditions:—

Firstly,—Obstruction to the escape of bile.