From this it is seen, that the pathology of jaundice, according to Frerichs, is very different from what we were formerly taught. For while he has entirely laid aside the theory of jaundice as a result of suppressed secretion, he has introduced two perfectly new elements--namely, abnormal diffusion, and diminished consumption. The latter theory, being, of course, founded on the supposition that bile, after playing its part in the digestive process, is re-absorbed into the circulation, again to perform another function in the animal economy, before its final excretion from the organism as effete matter. The theory of jaundice, hitherto most favoured in England, and which found {7} such an able exponent in Dr. Budd, is, that the disease may arise in two ways--firstly, by a mechanical obstruction to the passage of bile into the intestines, and the consequent re-absorption of the detained fluid into the blood; and secondly, by a suppression of the biliary secretion arising from some morbid condition of the liver itself, whereby the biliary ingredients accumulate in the circulation. Now, although I am not prepared to admit the justice of the views held regarding the origin and function of bile, on which these opinions are based, I nevertheless believe that in the following pages I shall be able, by the aid of modern medical science, to prove the correctness of the conclusions themselves. In order to do this, however, it will be necessary for me to begin by making a few remarks on the nature of bile, and the physiology of its secretion. ON THE NATURE OF BILE. In a few words, bile may be said to be composed of the following substances:-- Firstly,--Biliverdine, a green nitrogenized, non-crystallizable colouring matter, analogous to the green colouring matter of plants, and like it, leaving on incineration a distinctly ferruginous ash. This colouring matter appears, like {8} urohæmatine, and all other animal pigments, to be a direct derivative of the colouring matter of the blood.[2] [Footnote 2: _Vide_ papers by the author on the colouring matter of the urine, Pharm. Journ., November, 1852. "Urohæmatine, and its combination with animal resin." Verh. d. Phys.-Med. Gesellschaft zu Wurzburg, Bd. V. 1854.] [Illustration: FIG. 1. Crystals of Glycocholate of soda, a beautiful polariscopic object. _(a)_ Fine needle-shaped crystals, separated from a rosette-shaped group. _(b)_ Small rosette of crystals. _(c)_ Fan-shaped groups of crystals, which are merely portions of large rosettes that have become broken up. _(d)_ A fragment of a bundle of needle-shaped crystals. Mag. 90 diam.]