ALKALINITY OF THE BLOOD. 309 



by means of the pyknometer. For clinical purposes, where only small 

 amounts are available, it is best to proceed by the method as suggested 

 by HAMMERSCHLAG. Prepare a mixture of chloroform and benzene of 

 about 1.050 sp. gr. and add a drop of the blood to this mixture. If the 

 drop rises to the surface then add benzene, and if it sinks add chloroform. 

 Continue this until the drop of blood suspends itself midway and then 

 determine the specific gravity of the mixture by means of an areometer. 

 This method is not strictly accurate and must be performed quickly. 

 In regard to the necessary details refer to ZUNTZ and A. LEVY. 1 



The reaction of the blood is alkaline toward litmus, and various bodies 

 such as alkali carbonates, the phosphates, alkali-protein combinations, 

 the amino-acids and carbon dioxide all take part in bringing about the 

 normal reaction. According to HENDERSON 2 the normal reaction is 

 also partly brought about by ammonia formation and partly by the 

 phosphates, in that the kidneys secrete acid salts (phosphates) and return 

 alkali to the blood and regulate the reaction of the blood. 



In considering the alkalinity of the blood we must, as previously 

 remarked, differentiate between the amount of titratable alkali in the blood 

 and the true alkalinity, i.e., the amount of hydroxyl or hydrogen ions 

 in the blood. 



We have a large number of determinations of the quantity of titratable 

 alkali, calculated as Na2CO3, in fresh as well as defibrinated blood of 

 animals and man, and in the latter case under healthy and diseased con- 

 ditions. As these determinations have been carried out with dif- 

 ferent methods which were not without error they cannot be given any 

 great importance. The results found generally vary between 3 and 6 

 p. m. Na2COa and for man the figures below 3.3 p. m. and above 5.3 p. m. 

 are considered as pathological. The alkaline reaction diminishes out- 

 side of the body, and indeed the more quickly the greater the original 

 alkalinity of the blood. This depends on the formation of acid in the 

 blood, in which the red-blood corpuscles seem to take part in some way or 

 another. After excessive muscular activity the alkalinity is diminished 

 (PEIPER, COHNSTEIN), and it is also decreased after the continuous 

 ingestion of acids (LASSAR, FREUDBERG, 3 ) and others. 



1 Zuntz, Pfliiger's Arch., 66; Levy, Proceed. Roy. Soc., 71. 



2 Amer. Journ. of Physiol., 21, and Journ. of biol. Chem., 9; see also Robertson, 

 ibid., 6 and 7. 



3 Peiper, Virchow's Arch., 116; Cohnstein, ibid., 130, which also cites the works 

 of Minkowski, Zuntz, and Geppert; Freudberg, ibid., 125 (literature); in regard to the 

 methods for the estimation of the alkalinity see, besides the above-mentioned authors, 

 v. Jaksch, Klin. Diagnostik; v. Limbeck, Wien. med. Blatter, 18; Wright, The Lancet. 

 1897; Biernacki, Beitrage zur Pneumatologie, etc., Zeitschr. f. klin. Med., 31 and 

 32; Hamburger, Eine Methode zur Trennung, etc., Arch., f. (Anat. u.) Physiol. > 



