58 



are dissolved by the heat. It is a delicate test and will de- 

 tect one part of albumin in 20,000 of fluid. It has a value 

 as a quick test, since if no precipitate is formed after its 

 addition to the fluid, albumin is quite positively excluded. 



269. Add 2 volumes of strong alcohol to the urine in a 

 test-tube. The .solution will become cloudy and a precipitate 

 will form. Add a few drops of nitric acid and heat, if the 

 precipitate disappears it was composed of phosphates, if it 

 remains it is albumin. The test is a delicate one and will 

 detect I part of albumin in 32,000 of the solution. If the 

 albumin be very slight in amount it will require a number 

 of hours for the precipitate to form. The alcohol also pre- 

 cipitates peptones and does not precipitate alkaloids. 



270. Esbach's albuminometer method. Fill the tube 

 with urine to the letter U, then add the reagent to the letter 

 R. (The reagent is prepared by mixing 10 grams of picric 

 acid and 20 grams of citric acid and adding enough water to 

 make i liter. It is said that a i % solution of acetic acid 

 will give the same result). Invert the tube a number of 

 times so that the contents may be thoroughly mixed. Clo.se 

 the tube tightly with the rubber stopper and set aside for 

 24 hours. After which time the amount of dried albumin, 

 in one liter of urine can be read in grams on the tube. The 

 percentage is obtained by dividing by ten. Thus if the coag- 

 ulum stands at 3, the urine contains 3 parts of albumin per 

 thousand or 0.3%. If the albumin is very abundant (above 

 4) the urine should be diluted to obtain an accurate result. 

 I/e.ss than 0.5 per thousand of albumin cannot be accurately 

 estimated b}' this method. 



Caution. The coagulable substance found in the urine of 

 Bright's disease is a mixture of ".serum-albumin" and 

 ".serum-globulin" or "para-globulin" Saturation of the 

 urine with crystallized magnesium sulphate precipitates the 

 "serum-globulin", leaving the serum-albumin in splution. 



271. Centrifugal method. The percentage tube is filled 



