472 Veterinary Medicine. 



orange brown, and may leave a correspondingly deep stain on 

 white paper. 



The test for bile pigments (Gmelin's) is simple and beautiful. 

 Pour a little nitric acid into a test tube held obliquely and then 

 add a few drops of sulphuric acid, and finally a little urine, so 

 slowly, that it will remain on the surface. Soon at the point of 

 junction appear in succession the various colors of the rainbow : 

 yellow, green, blue, violet, red and lastly a dirty yellow. It is 

 open to this objection that the characteristic play of colors may 

 be produced by alcohol in the absence of bile pigments. Indican 

 also will produce the green and yellow with blue between but 

 never the violet nor red, nor all in their regular order. 



A second mode of applying this test is by spreading a few drops 

 of the urine on a white plate and letting fall a drop of nitric acid 

 in the centre. The play of colors is very characteristic. 



The test for bile acids (Pettenkofer's) is to place a portion of 

 the urine in a test tube, and after adding a drop of syrup, to add 

 cautiously, drop by drop, two-thirds of the amount of sulphuric 

 acid. Shake the mixture and set aside for some minutes. If 

 sufficient heat is not produced by the mixing of the acid and 

 urine warm slightly. The mixture becomes of a dark violet 

 color which is destroyed by a temperature a little above 140° Fah. 



A convenient application of this test (Stranburg) is to add a 

 little cane sugar to the urine, dip a piece of filtering paper in the 

 mixture, dry it thoroughly, pour a drop of sulphuric acid on the 

 paper and allow it to run partially off. In a quarter of a minute 

 a beautiful violet color is produced, best seen by holding up the 

 paper to the light and looking through it (Brunton). 



In cases due to obstruction of the bile ducts the dung is desti- 

 tute of bile, whitish, often clayey and fcetid, while in cases due 

 to reabsorption without obstruction the faeces have their natural 

 color and odor. 



It is needless to enumerate all the concomitant symptoms of 

 jaundice which will be better noticed under the different disorders 

 which determine it, for a list of which see the causes. 



The gravity of the affection will depend on the dangerous 

 nature of these concurrent diseases, and the destructive changes 

 in the liver and blood rather than on the depth of color in the 

 textures, 



