304 THE URINE. 



in intensity with the amount present. Concentrated urines should 

 first be diluted. Albumoses are also thrown down, but are redis- 

 solved on boiling and reappear on cooling. Should nucleo-albu- 

 mins be present beyond traces, a precipitate develops upon the 

 addition of the acetic acid. This may also occur if urates are 

 present in large amounts. But in this event the precipitate clears 

 upon warming the solution ; and if the urine, moreover, is previously 

 diluted, it does not occur at all, while the separation of nucleo-albu- 

 min takes place more rapidly in the latter case than before. 



Still other tests exist which are equally good, but for practical 

 purposes the three just described will suffice. In every case, 

 however, it is necessary that the urine should be perfectly clear. 

 If turbid, owing to precipitation of any of the normal constit- 

 uents of the urine, simple nitration generally suffices ; but if refer- 

 able to bacteria, it is best shaken with powdered talcum and then 

 filtered. 



Special Test for Serum-albumin. If it is desired to demonstrate 

 the presence of serum-albumin by itself, the urine is rendered 

 amphoteric or faintly alkaline with sodium hydrate, and satu- 

 rated with magnesium sulphate to remove any globulins that may 

 be present. The filtrate is then acidified with acetic acid and boiled, 

 when in the presence of serum-albumin precipitation occurs. 



Special Test for Serum-globulin. This is conducted as above, 

 or by adding an equal volume of a saturated solution of ammo- 

 nium sulphate to the amphoteric urine, when the globulins are 

 thrown down. Urates may then also separate out, but this always 

 occurs later. The precipitated globulins are soluble in acetic acid. 

 As I have stated before, there is one instance of globulinuria on 

 record in which the substance was found in the sediment in crystal- 

 line form. 



Test for Nucleo- albumin. A small amount of urine is diluted 

 with water and then treated drop by drop with strong acetic acid. 

 In this manner the precipitation of urates is prevented, while the 

 nucleo-albumin separates out. To identify it as such, however, it is 

 necessary to isolate the substance in larger amounts. To this end, 

 the collected urine of twenty-four hours is carefully neutralized and 

 concentrated to about 1000 c.c. at a temperature of 60-70 C. On 

 filtering, it is saturated with ammonium sulphate in substance and 

 the precipitate collected on a filter. This is dissolved in a little 

 water and freed from salts by dialysis. Should hetero-albumose be 

 present, this separates out and is removed by filtration. A portion 

 of the remaining solution is then tested with acetic acid, as described ; 

 the precipitate should be soluble in mineral acids. In the remaining 

 solution the body is completely thrown down with acetic acid. The 

 precipitate is filtered off, washed with dilute acetic acid, and dried. 

 On fusion with caustic alkali and potassium nitrate, phosphoric acid 

 should then be liberated if. the substance is a nucleo-albumin. If 

 this reaction is not obtained, but if on boiling with dilute mineral 



