be taking no highly-coloured food, or any of the medicines above indicated, the stools are of a {54} dirty pipe-clay colour. This is not due to the presence of any new or foreign matter, but solely to the absence of bile pigment. In these cases the evacuations, besides being white, are usually of a most offensive odour, for, among other things, bile checks intestinal putrefaction, and the development of offensive gases. In addition to the colour, and odour of the fæces, in cases of jaundice, another important indication is to be found in the presence of fat. The presence of fat in the stools was at one time looked upon as evidence of pancreatic, at another time of hepatic disease; now, however, experimental physiology has taught us, that it in some measure depends upon both. For while, on the one hand, the pancreatic secretion emulsions the fatty part of our diet, and thereby renders it capable of absorption, recent researches, as has been already pointed out, have established the fact that the biliary secretion also plays an important part in the absorption of the oleaginous constituents of our food. Bidder and Schmidt, as was before said, have shown that a dog, after ligature of the gall-duct, absorbs less than half the average normal quantity of fat; and by experiment it has been found that this arises from the circumstance that bile emulsions only the acid fats, while pancreatic juice transforms the neutral as well as the acid {55} oleaginous matters. The presence of fat in the stools may be due, therefore, partly to hepatic, partly to pancreatic derangement; and I shall immediately point out how we can turn this fact to account in diagnosis, and discover in cases of jaundice from obstruction, whether the seat of the obstruction be at the outlet or in the course of the duct. EXAMINATION OF THE RENAL SECRETION. The urine affords us important information in all cases of jaundice. In fact, an examination of it alone would in many cases enable us to discover the presence or absence of this affection. _Diagnostic Value of the Colour of the Urine._