258 THE BLOOD. 



P. MAYER, LEPINE and BOULUD l . The last two investigators find two 

 definite glucuronic acids in the blood, both of which are levorotatory. 

 One reduces FEHLING'S solution even at a temperature below 100, 

 while the other reduces it at above 100. Such large amounts of the first 

 acid often occur in the blood of dogs that the optical activity of the glucu- 

 ronic acid counteracts that of the glucose: The second acid also occurs 

 in larger quantities as compared with the sugar. 



BERNARD 2 has shown that the quantity of sugar in the blood 

 diminishes more or less rapidly on leaving the veins. LEPINE, associated 

 with BARRAL, has specially studied this decrease in the quantity of 

 sugar, and calls it glycolysis. LEPINE and BARRAL, as well as ARTHUS, 

 have shown that this glycolysis takes place in the complete absence of 

 micro-organisms. It seems to be due to a soluble glycolytic enzyme whose 

 activity is destroyed by heating to 54 C. This enzyme is derived, 

 according .to the above investigators, from the leucocytes and, accord- 

 ing to ARTHUS as well as to DOYON and MOREL 3 it occurs only in the 

 serum but not in the plasma. According to LEPINE, 4 it has some con- 

 nection with the pancreas. The glycolysis is, according to ROHMANN 

 and SPITZER and SiEBER, 5 an oxidation which is produced, according 

 to the two last-mentioned investigators, by an oxidation ferment. There 

 is still some doubt whether this is a physiological process or not. 6 



The blood-plasma and the serum, as well as the lymph, also contain 

 enzymes of various kinds. According to ROHMANN, BIAL, HAMBURGER/ 

 and others, diastases, which convert starch and glycogen into maltose or 

 isomaltose, as well as a maltase, are found in the blood. HANRIOT has 

 detected in the serum a lipase which decomposes butyrin, and which, 

 according to him, decomposes neutral fats and other esters. The occur- 



1 Mayer, Zeitschr. f. physiol. Chem., 32; Lepine and Boulud, Compt. rend., 133, 

 135, 136, 138, 141, and Journ. de Physiol., 7 (cited from Biochem. Centralbl., 4, p. 421). 



2 Lemons sur le diabete, Paris, 1877. 



3 Arthus, Arch, de Physiol. (5), 3; Doyon and Morel, Compt. rend. soc. biol., 55. 



4 In regard to the numerous memoirs of Lupine and Lepine and Barral, see Lyon 

 medical., 62 and 63; Compt. rendus, 110, 112, 113, 120, and 139; Lepine, Le ferment 

 glycolytique et la pathogenic du diabete (Paris, 1891), and Revue 'analytique et 

 critique des travaux, etc., in Arch, de med. expe"r. (Paris, 1892) ; Revue de medecine, 

 1895; Arthus, Arch, de Physiol. (5), 3, 4; Nasse and Framm, Pfliiger's Arch., 63, 

 Paderi, Maly's Jahresber., 26; see also Cremer, Physiologie des Glykogens in Ergebnisse 

 d. Physiol., l,Abt. 1. 



5 Rohmann and Spitzer, Ber. d. d. chem. Gesellsch., 28; Spitzer, Pfluger's Arch., 

 60 and 67; Sieber, Zeitschr. f. physiol. Chem., 39 and 44. 



6 See Arthus, 1. c.; Colenbrander, Maly's Jahresber., 22; Rywosch, Centralbl. f. 

 Physiol., 11, 495. 



7 Rohmann; Rohmann and Hamburger, Ber. d. deutsch. chem. Gesellsch., 25 and 

 27; Pfluger's Arch., 52 and 60; Bial, Ueber das diast. Ferm., etc., Inaug.-Diss. Breslau, 

 1892 (older literature). See also Pfluger's Arch., 52, 54, and 55 



