HYDROGEN-ION CONCENTRATION 



35 



in the accompanying chart. The H-ion concentration of the unknown 

 solution is that of the tint with which it matches in the series. 



It might be thought that this method would be inaccurate because of 

 the loss of carbon dioxide from the blood. By actual experiment, how- 

 ever, it has been found that, if the blood is collected with certain pre- 

 cautions, the error is negligible. The method is, therefore, a most useful 

 one clinically. 



To minimize the chances of loss of free C0 2 , S. H. Dale and Evans have 

 elaborated the technic of the dialysis method by tying the sac onto an 

 ebonite perforated stopper which exactly fits the mouth of the test tube 

 containing the neutral saline solution. The blood is delivered directly 

 from the blood vessel by a narrow glass tube which passes to the bottom 

 of the sac through the hole in the stopper. After enough blood has been 

 collected the tube is withdrawn and the hole in the stopper is tightly 

 closed by a piece of cork. We have found this a useful method but we 

 do not believe that the further modification described in their paper for 

 determination of the P H of the dialysis is as reliable as that described 

 above. 20 



The following table gives the hydrogen-ion concentration or true 

 reaction of the body fluids. 



FLUID 



PH 



FLUID 



PH 



Blood 7.4 



Urine 6.0 



Saliva 6.9 



Gastric juice (adult) 0.9-1.6 



Gastric juice (infant) 5.0 



Pancreatic juice (dog) 8.3 



Small intestinal contents 8.3 

 Small intestinal contents (infant) 3.1 



Bile from liver 7.8 



Bile from gall bladder 5.3-7.4 



Perspiration 7.1 



Perspiration 4.5 



Tears 7.2 



Muscle juice (fresh) 6.8 



Muscle juice (autolyzed) Variable 



Pancreas extract 5.6 



Peritoneal fluid 7.4 



Pericardial fluid 7.4 



Aqueous humor 7.1 



Vitreous humor 7.0 



Cerebrospinal fluid (fresh) 7.4 

 Cerebrospinal fluid (after standing) 8.3 



Amniotic fluid 7.1 



Amniotic fluid 8.1 



Milk (human) 7.0-7.2 



Milk (cow) ' 6.6-6.8 



Milk (goat) 6.6 



Milk (ass) 7.6 



(W. M. Clark and H. A. Lubs.) 





