326 PHYSIOLOGICAL CHEMISTRY 



faintly acid so that any bicarbonate present will be converted to carbonate. 

 Note the number of grams of bicarbonate necessary to produce an alkaline urine. 



Interpretation. Normally the administration of from 5 to 10 grams 

 of bicarbonate is generally sufficient to produce an alkaline reaction 

 in the urine, 1 while in patients suffering from acidosis a greater amount 

 is required. In general a maximum ingestion of 0.5 gram of bicarbonate 

 per kilogram body weight will produce an alkaline urine in a normal 

 person. In mild acidosis this value may be increased to a maximum 

 of 0.8 gram, whereas, moderate acidosis may show a value of i.i 

 grams. In severe acidosis with symptoms of acid intoxication the 

 bicarbonate value may exceed i.i grams per kilogram body weight. 

 If an alkaline urine is obtained after the administration of 0.5 gram 

 or less of bicarbonate per kilogram body weight one is safe in saying 

 that no acidosis exists. When higher values are obtained, however, 

 they should be Confirmed by blood analysis before being accepted. 

 For data as to alkali tolerance under different conditions see table on 

 page 317. 



6. Relative Hydrogen Ion Concentration of the Blood. Method of Levy, 

 Rownlree, and Marriott? Principle. The blood is dialyzed against normal salt 

 solution and the H ion concentration of the protein-free dialyzate is determined 

 by the indicator method, using phenolsulphonephthalein. 



Procedure. One to 3 c.c. of clear serum or of blood is run, by means of a 

 blunt-pointed pipette, into a dialyzing sac 3 which has been washed outside and 

 inside with salt solution. 4 The sac is lowered into a small test-tube (100X10 

 mm., inside measurements), containing 3 c.c. of salt solution, until the fluid on the 

 outside of the sac is as high as on the inside. From 5-10 minutes are allowed for 



1 Henderson & Palmer: Jour. Biol. Chem. 14,81, 1913. 



2 Levy, Rowntree and Marriott: Arch. Int. Med., 16, 389, 1915. 



3 Preparation of Sacs. One ounce of celloidin is dissolved in 500 c.c. of a mixture of 

 equal quantities of ether and ethyl alcohol. The solid swells up and dissolves with oc- 

 casional gentle shakings, in 48 hours. As a small amount of brown sediment separates 

 out at first, the solution should stand for at least three or four days, after which the clear 

 supernatant solution is ready for use. A small test-tube (120 by 9 mm., inside measure- 

 ment) is filled with this mixture, inverted, and half the contents poured out. The tube is 

 then righted, and the collodion allowed to fill the lower half again. A second time it is 

 inverted and rotated on its axis, the collodion being drained off. Care must be taken to 

 rotate the tube, in order to secure a uniform thickness throughout. The tube is clamped 

 in the inverted position and allowed to stand for ten minutes, until the odor of ether finally 

 disappears. It is filled five or six times with cold water, or it is allowed to soak five minutes 

 in cold water. A knife blade is run around the upper rim, so as to loosen the sac from the 

 rim of the test-tube, and a few cubic centimeters of water are run down between the sac 

 and the glass tube. By gentle pulling the tube is extracted, after which it is preserved by 

 complete immersion in water. 



4 The Salt Solution. The blood or serum is dialyzed against an 0.8 per cent sodium 

 chloride solution. 



Before applying the test, it is necessary to ascertain that the solution is free from acids 

 other than carbonic. To determine this, a few cubic centimeters of the salt solution are 

 placed in a Jena test-tube and i or 2 drops of the indicator added, whereupon a yellow color 

 appears. On boiling, carbon dioxide is expelled, and the solution loses its lemon color 

 and takes on a slightly brownish tint. In the absence of this change other acids are 

 present, and the salt solution is therefore not suitable. If, on the other hand, on adding 

 the indicator pink at once appears, the solution is alkaline and hence cannot be used. 



