DISEASES OF THE LIVER. 735 



always be attended to ; that wlien slieep are put upon turnips, 

 nitrogenous food should be allowed them throughout the whole 

 turnip season in some shape or other, as hay, straw, or small 

 quantities of cahe, or bean meal. 



JAUNDICE — ICTERUS, OR THE YELLOWS. 



Although spoken of as a disease, jaundice is in reality but a 

 symptom of many affections in which the tissues of the body 

 are dyed yellow. Although a result of many organic diseases of 

 the liver, it sometimes occurs when that organ is healtliy, and is 

 not rarely absent when it is in a state of disorganization. It 

 may be produced artificially by ligature of the common duct, 

 which proves that obstruction of the flow of bile into the intes- 

 tine can cause the disease. It may also occur when there is no 

 such obstruction. And to account for these varieties of causes 

 various theories have been advanced : — First, that the bile is 

 formed in the blood, and is merely removed by the liver, and that 

 jaundice is a consequence of non-separation of the bile; second, that 

 in some diseases the htematin of the blood is changed into bile- 

 pigment, with disintegration of a large number of blood cor- 

 puscles, thus assigning a blood origin to the colouring matter of 

 jaundice ; tliird, that it arises from abnormal diffusion of bile, 

 proceeding from some alteration in the circulation of the blood 

 in the liver, or else to defective metamorphosis or impaired con- 

 sumption of bile in the blood. It is now, however, generally 

 admitted that some of the ingredients of the bile are generated 

 in the liver — namely, the bile acids, glycocholic and taurocholic 

 acids found in the bile combined wnth soda bases ; whilst others 

 — the bile pigment, biliverdine, bilirubin, or cholepyrrhin and 

 cholesterine — exist in the blood, and are merely separated by the 

 liver in a manner similar to the separation of the urea from 

 the blood by the kidneys. It is now admitted that jaundice 

 may arise from two distinct causes : — 1st. Suppression or non- 

 elimination ; and 2d. From reabsorption of bile. 



The two forms are distinguished by the presence of the 

 biliary acids in the urine when it arises from reabsorption, and 

 their absence when due to suppressed secretion. The test 

 is as follows : — To a couple of drachms of the suspected urine 

 add a small fragment of Joaf sugar, and afterwards pour slowly 



