Physical Properties of the Urine. 199 



lime water to the urine, and the white oxalate of lime is precipi- 

 tated. 



Allantoin (C^HgN^O,) is found in the urine of sucklings 

 (calves) during the first few weeks of life, in pregnancy and 

 when on a meat diet. It diminishes witli the increase of vege- 

 table food. 



Xanthin (C^H^N^Oj) is found in urine as a result of imperfect 

 oxidation of nitrogenous matters especially, which would other- 

 wise pass into uric or hippuric acid. Its immediate antecedents 

 in such transformation are guanin and hypoxanthin or sarkin. 

 It is a rare constituent of urinary calculus. 



Hypoxanthin (C-H^N^O) is produced from fibrine in ga.stric 

 and pancreatic digestion and in putrefaction, and is especially 

 abundant in leucsemic subjects. 



Cyanuric Acid ( C.,oHj^N.^Oj. ) occurs in dog's urine. 



Leucin (CgHjgNO^) and Tyrosin (CgHuNOj) are products of 

 pancreatic digestion of proteids, and the former occurs normally in 

 the spleen, thymus, thyroid, iiver, salivary glands, and urine. 

 Both are present in large amount, in the urine, in acute atrophy 

 of the liver. Test for leucin : Evaporate carefully to dryness 

 with nitric acid : the residue, if leucin, will be almost transparent 

 and turn yellow or brown on the addition of cau.stic soda.- If now 

 heated with the soda it forms an oily drop. Test for tyrosin : 

 treated with .strong sulphuric acid, gently warmed and chloride 

 of iron added, it gives a violet color. 



Albumen is an important morbid constituent of urine, which 

 appears in a great variety of diseases (nephritis, pneumonia, 

 epilep.sy, anaemia, leuccemia. diabetes, hsematuria, haemoglobi- 

 tmria, hydraemia, infectious lung diseases, cardiac obstruction, 

 venous stasis in the kidney, dermatitis, burns, lesions of the 

 crura cerebri, floor of the fourth ventricle, spinal cord, or renal 

 vaso motor nerves). It also occurs after violent exertion, in 

 poisoning by strong acid, phosphorus, arsenic, lead, mercury, 

 opium or alcoliol, and when an exce.ss of albumen is injected into 

 the blood. All forms of albumen may enter the urine, but the 

 most conunon are serum albumen, globulin of serum, propeptone 

 and peptone. A simple test is to acidulate the urine with acetic 

 acid and lioil : if the precipitate does not dissolve on addition of 

 nitric acid, it is albumen. Sulphosalicylic acid added to tlie urine 

 will cause a precipitate in urine containing only -50^-5^0^0^ of albumen. 



