§ 295. =Diagnostic Differences between Acute Yellow Atrophy of the Liver and Fatty Liver produced by Phosphorus.=--O. Schultzen and O. L. Riess have collected and compared ten cases of fatty liver from phosphorus poisoning, and four cases of acute yellow atrophy of the liver, and, according to them, the chief points of distinction are as follows:--In phosphorus poisoning the liver is large, doughy, equally yellow, and with the acini well marked; while in acute yellow atrophy the liver is diminished in size, tough, leathery, and of a dirty yellow hue, the acini not being well mapped out. The “phosphorus” liver, again, presents the cells filled with large fat drops, or entirely replaced by them; but in the “atrophy” liver, the cells are replaced by a finely-nucleated detritus and through newly-formed cellular tissue. Yellow atrophy seems to be essentially an inflammation of the intralobular connective tissue, while in phosphorus poisoning the cells become gorged by an infiltration of fat, which presses upon the vessels and lessens the blood supply, and the liver, in consequence, may, after a time, waste. There is also a clinical distinction during life, not only in the lessening bulk of the liver in yellow atrophy, in opposition to the increase of size in the large phosphorus liver, but also in the composition of the renal secretion. In yellow atrophy the urine contains so much leucine and tyrosin, that the simple addition of acetic acid causes at once a precipitate. Schultzen and Riess also found in the urine, in cases of yellow atrophy, _oxymandelic acid_ (C₈H₈O₄), but in cases of phosphorus poisoning a nitrogenised acid, fusing at 184° to 185°. According to Maschka, grey-white, knotty, fæcal masses are found in the intestines in yellow atrophy, but never in cases of phosphorus poisoning. In the latter, it is more common to find a slight intestinal catarrh and fluid excreta. § 296. =The Detection of Phosphorus=.--The following are the chief methods in use for the separation and detection of phosphorus:[313]-- [313] It has been recommended to dissolve the phosphorus out from organic matters by carbon disulphide. On evaporation of the latter the phosphorus is recognised by its physical properties. Such a method is of but limited application, although it may sometimes be found useful. I have successfully employed it in the extraction of phosphorus from the crop of a fowl; but on this occasion it happened to be present in large quantity.