GL YCO GENESIS— THE OR Y OF BERNARD. 9 2 3 
the body, gives off such material into the blood in the form of dextrose. 
This dextrose is taken to the tissues ami is used by them, becoming 
oxidised within them. Whether this oxidation occurs outside the actual 
bioplasm, or whether the dextrose which is taken to the bioplasm 
becomes first of all built up into its molecules and then split up 
and oxidised, and whether the products of its oxidation leave the 
muscles in their ultimate forms, are questions which we need not 
now consider. In either case the effect of such oxidation is to produce 
energy (in the form of heat and mechanical work). 
This view of Bernard's has, on the whole, met with general favour among 
physiologists. Some there are, indeed, who have so far proceeded beyond 
Bernard, as to assert that the icltole energy of the body is derived from the 
oxidation of carbohydrate. Such carbohydrate, which is taken to the tissues 
in the blood in the form of glucose, is assumed to be formed either from the 
stored carbohydrate of the liver, as Bernard supposed, or independently of this 
from proteid, or even from fatty materials in the liver cells, and being carried 
to the tissues to be taken up by them, oxidised within them, and thus become 
the immediate source of the energy of the body, whether this takes the 
form of heat or work. It is in fact assumed that the main result of 
metabolism within the body is the production in one part, and the destruction 
in another, of carbohydrate. Such a view has been chiefly contended for by 
Seegen 1 and Chauveau, who hold that even the proteid material of the food, 
at least its non-nitrogenous part, must ultimately become converted into 
carbohydrate before it can become oxidised in the tissues (see p. 914). 
It is obvious that Bernard's theory is, in the main, dependent upon the 
circumstance that sugar is continually being passed from the liver into the 
hepatic blood, even during starvation, and this, in fact, has been directly 
affirmed by Bernard and others. Even in the fasting animal, sugar is found in 
the blood, except at the extreme end of an inanition period ; and, according to 
the analyses of Seegen, it always occurs in larger amount in the hepatic blood, 
whatever be the nature of the food, whether proteid, fat, or carbohydrate, 
than in blood from any other source. Tbis occurrence of dextrose in 
larger proportion in the hepatic blood than in the rest of the blood of the 
body, if it were completely and satisfactorily determined, would be a fact of 
fundamental importance, and would go very far to establish Bernard's theory 
upon a firm basis. But there are reasons for believing that such an excess of 
sugar as has been found by Seegen and other observers is not present 
under absolutely normal conditions. Seegen's experiments were made without 
anaesthetics, and it is a well-established fact that any operation upon an 
animal, which involves the production of pain, will immediately produce 
a transformation of the glycogen of the liver into sugar, and the appearance of 
an excess of sugar in the hepatic blood. 2 It is, in fact, admitted by Seegen 
1 "Die Zuckerbildung im Thierkbrper, " Berlin, 1890, S. 218, and numerous papers in 
the Arch. f. d. yes. Physiol., Bonn, and in the Ccntralhl. f. Physiol., Leipzig u. Wien. 
2 Seegen calculates that in man from 500 to 1000 grms. of dextrose may pass into 
the blood from the liver in twenty-four hours. But since his calculations are based upon 
experiments made upon animals in an abnoimal condition so far as the carbohydrate 
metabolism is concerned, these numbers cannot be accepted. Cf. Abeles, Med. Jahrb., 
Wien, 1886, S. 383; I. Munk, Perl. Mia. Wchnschr., 1S90, S. 595; also Pmiger, 
Arch. f. d. yes. Physiol., Bonn, 1891, Bd. 1. S. 330, 396 ; Mosse, ibid., 1896, Bd. lxiii. S. 
613 ; Zuntz, Ccntralhl. f. Physiol., Leipzig u. "Wien, 1896, S. 561. The blood is obtained 
either directly from one of the hepatic veins, or by passing a catheter up into the inferior 
cava, this vein being then blocked just below the reception of the hepatic veins by the 
inflation of an india-rubber bag ; or a tube is passed down from the jugular vein through 
the right auricle into the inferior cava, and its bent end is made to enter one of the 
hepatic veins. 
