APPENDIX 467 



marked deviation in quantity and as the deviation is usually very well marked, 

 a method giving only fairly accurate results is sufficient for their estimation. 



Dilute 5 c.c. of the urine, which should be free from albumin, with 50 to 75 c.c. 

 of distilled water, add 10 to 15 drops of a solution of potassium chromate and then 

 from a burette add N/io AgNO 3 until a very slight pinkish tinge is obtained. 

 The number of cubic centimeters of AgN0 3 required, multiplied by 0.00585 will 

 give the quantity of sodium chloride to which the chlorine in 5 c.c. of urine is 

 equivalent. Where a considerable degree of accuracy is demanded one should use 

 either the Arnold or the Harvey modification of Volhardt's method. 



FORMALDEHYDE IN URINE AFTER ADMINISTRATION OF UROTROPIN 



As formaldehyde fails to appear in the urine of possibly 52% of those taking 

 urotropin as a geni to-urinary antiseptic in quantities sufficient to inhibit bacterial 

 growth (1-5000) the usual tests are too delicate. As a practical guide to efficient 

 breaking up of urotropin the test proposed by Burnam is to be recommended. 



To about 10 c.c. urine in a test-tube at body temperature add 3 drops of Y^% 

 solution of phenylhydrazin hydrochloride and 3 drops of a 5% solution of sodium 

 nitroprusside. Finally allow a few drops of 20% solution of NaOH to run down 

 the side of the test-tube and as this diffuses throughout the urine a deep purplish-blue 

 color, rapidly changing to a dark green becoming lighter green and finally pale 

 yellow will show if formaldehyde is being excreted in sufficient strength. In the 

 absence of sufficient formaldehyde a reddish color develops which finally turns to a 

 light yellow. 



In order to obtain effect from urotropin it is necessary to have the urine acid. 

 This is best accomplished, if an acid reaction is absent, by the administration of 

 dihydrogen sodium phosphate (acid sodium phosphate). In carrying out Burnam 

 test albumin in the urine confuses the color reaction. By careful boiling to 

 precipitate the albumin, then filtering, we avoid confusing colors. 



Phenolsulphonephthalein Test for Renal Efficiency 



. Geraghty has recently stated that in 35 cases where an autopsy made it possible 

 to verify the accuracy of this test the lesions revealed at autopsy corresponded 

 closely with the results of the test. Again in 30 nephrectomies the conditions 

 found were in accordance with the results of the test. The general opinion of 

 those who have used the test is that it is more reliable than cryoscopy and far easier 

 of application. The technic is as follows: One c.c. of the phthalein solution 

 containing 6 mg. is injected intramuscularly or subcutaneously. The drug can be 

 bought in ampules ready for use. About twenty minutes before injecting the drug 

 the patient is given from 200 to 400 c.c. of water to drink. After the injection the 

 bladder is emptied with a catheter and the time is accurately noted when the urine 

 which subsequent to the emptying of the bladder and being allowed to drop into a 

 test-tube containing i drop of a 25% sodium hydrate solution first shows a pinkish 

 tinge. This is recorded as the time of appearance of the drug in the urine and 

 normally is about ten minutes. The catheter is then withdrawn and the urine that 

 is passed in the first hour collected and subsequently that passed in the second hour. 



