3l6 PHYSIOLOGICAL CHEMISTRY. 



3. Spiegler's Ring Test. Place 5 c.c. of Spiegler's reagent 1 in 

 a test-tube, incline the tube, and, by means of a pipette, allow 5 c.c. 

 of urine, acidified with acetic acid, to flow sloivly down the side. A 

 white zone will form at the point of contact. This is an exceedingly 

 delicate test, in fact, too delicate for ordinary clinic'al purposes, 

 since it serves to detect albumin when present in the merest trace 

 (i 1250,000) and hence most normal urines will give a positive re- 

 action for albumin when this 'test is applied. 



Some investigators claim that the delicacy of this test depends 

 upon the presence of sodium chloride in the urine, the test losing 

 accuracy if the sodium chloride content be low. 



4. Jolles' Reaction. Shake 5 c.c. of urine with i c.c. of 30 per 

 cent acetic acid and 4 c.c. of Jolles' reagent 2 in a test-tube. A white 

 precipitate indicates the presence of albumin. 



Care should be taken to use the correct amount of acetic acid, 

 since the use of too small an amount may result in the formation of 

 mercury combinations which may cause confusion. In the presence 

 of iodine, mercuric iodide will form but may readily be differenti- 

 ated from albumin through the fact that it is soluble in alcohol. 



5. Coagulation or Boiling Test. (a) Heat 5 c.c. of urine to 

 boiling in a test-tube. A precipitate forming at this point is due 

 either to albumin or to phosphates. Acidify the urine slightly by 

 the addition of 3-5 drops of very dilute acetic acid, adding the acid 

 drop by drop to the hot solution. If the precipitate is due to phos- 

 phates it will disappear under these conditions, whereas if it is due 

 to albumin it will not only fail to disappear but will become more 

 flocculent in character, since the reaction of a fluid must be acid to 

 secure the complete precipitation of the albumin by this coagulation 

 process. Too much acid should be avoided since it will cause the 

 albumin to go into solution. Certain resin acids may be precipi- 

 tated by the acid, but the precipitate due to this cause may be easily 

 differentiated from the albumin precipitate by reason of its solubility 

 in alcohol. 



1 Spiegler's reagent has the following composition : 



Tartaric acid 20 grams. 



Mercuric chloride 40 grams. 



Glycerol 100 grams. 



Distilled water 1000 grams. 



2 Jolles' reagent has the following composition : 



Succinic acid 40 grams. 



Mercuric chloride 20 grams. 



Sodium chloride 20 grams. 



Distilled water . 1000 grams. 



