APPENDIX 457 



The amount of urine varies in different individuals (water or beer habit). It is 

 usually given as from 1000 to 1500 c.c. 



Long proposes to substitute 2.6 for Haeser's coefficient which, if multiplied by 

 the two final figures of the specific gravity taken at 25C., gives the weight of urin- 

 ary solids in 1000 c.c. 



Albumin. Practically serum albumin alone is clinically important. 



The two usual tests are i. Heat test and 2. Heller's nitric acid test. For the 

 former, add 3 to 10 drops of 5% acetic acid to the perfectly clear urine in a test- 

 tube and bring to a boil. By boiling the upper portion a turbidity in contrast with 

 the clear lower portion may be obtained. I usually prefer to heat the urine and after 

 the boiling add the 5% acetic acid, drop by drop. This will clear up the turbidity 

 due to phosphates. 



A more delicate test for albumin is the following: Add to a test-tube half filled 

 with filtered urine one-fifth its volume of a saturated aqueous solution of sodium 

 chloride; heat to the boiling-point; add 2 to 5 drops of 50% acetic acid and 

 heat again. This test may serve to distinguish nucleo-albumin, as most forms of 

 nucleo-proteid found in urine do not react to the test, while serum albumin does. 

 Thus where a positive nitric acid test is present, and no precipitate occurs with 

 this test, the proteid present is usually nucleo-proteid. 



For Heller's test, pour a small amount of nitric acid into a narrow test-tube 

 and, while holding the tube at an angle of about 45 degrees, superimpose a layer of 

 the urine to be tested, which is delivered drop by drop from a pipette and allowed 

 to flow down the side of the tube. 



This test can be converted into a quantitative one which is sufficiently accurate 

 for clinical purposes. It is based on the fact that a specimen of urine containing 

 0.003 % of albumin will give a perceptible ring at the layering of the urine and acid 

 in two minutes. If the ring appears at once or in a few seconds" the albumin con- 

 tent is greater. From the qualitative test an idea can be formed as to the amount 

 of albumin which the urine contains, a heavy ring forming immediately showing a 

 considerable albumin content. Probably the highest elimination of albumin is 

 found in chronic parenchymatous nephritis where it may run from i to 3%. In 

 an ordinary case of acute nephritis 0.5% would be an average content. 



Recently I have been using for both qualitative and quantitative albumin tests 

 the apparatus shown in Fig. 7. This is simply a 5-inch piece of ^-inch soft 

 glass tubing heated at a point 2 inches from one end, drawn out about 2 inches 

 and bent to form a U tube with one end shorter than the other. This form of 

 tube enables one to perform two tests with the same column of nitric acid and is 

 easily cleaned and dried. They may be kept suspended around a glass tumbler's 

 rim. Taking up a small amount of nitric acid with a capillary bulb pipette it is 

 deposited in the capillary curve of the bent tube. This acid pipette should be 

 kept attached to the acid bottle. With a second pipette the urine is deposited in 

 the short arm of the U tube and the presence of albumin shows by a distinct ring 

 at the junction of urine and acid in the clear capillary tubing. The long arm will 

 serve for the introduction of a different specimen of urine for the albumin test. 



For quantitative test we dilute the filtered urine with one or more parts of nor- 

 mal salt solution according to the intensity of the albumin ring. A very convenient 

 way of making the dilution is with a graduated centrifuge tube. Make a i to 



