- eter and two feet wide. 
AveustT 16, 1918] 
in the tissues possessing the property of liber- 
ating oxygen from hydrogen peroxide. Hence 
the conclusion was drawn that catalase is the 
enzyme in the body principally responsible 
for oxidation. Stated more specifically, the 
present investigation was carried out to deter- 
mine if the end prodicts of digestion of food, 
when absorbed from the alimentary tract and 
earried to the liver, stimulate this organ to an 
increased output of catalase, which being taken 
to the muscles and tissues increase oxidation, 
and if during exercise the liver was also stimu- 
lated to an increased output of catalase, 
thereby increasing oxidation in the muscles 
and thus furnish the energy for exercise. 
The animals used were cats, rabbits and 
dogs. The catalase in 0.5 c.c. of the blood of 
the animals was determined by adding this 
amount of blood to hydrogen peroxide in a 
bottle at 22° C. and as the oxygen gas was 
liberated, it was conducted through a rubber 
tube to an inverted burette previously filled 
with water. After the volume of gas thus 
collected in ten minutes had been reduced to 
standard atmospheric pressure, the resulting 
volume was taken as a measure of the amount 
of catalase in the 0.5 ¢.c. of blood. The mate- 
rial was shaken at a fixed rate of one hun- 
dred and eighty double shakes per minute 
during the determinations. The animals were 
exercised in a tread-wheel seven feet in diam- 
The food materials 
were carbohydrates (maltose, levulose, dex- 
trose, lactose, honey, cane sugar, cornstarch, 
dextrin, wheat flour, corn meal, rice flour and 
fruits (oranges, lemons, apples, bananas, grape- 
bean flour) ; fats (olive oil, bacon, cream, cod- 
liver oil, glycerine, palmitic acid and lard); 
fruit and rhubarb); proteins (egg, beef, beef 
extract, beef juice, aminoids and peptone); 
beverages (coffee, milk, chocolate, tea and 
cocoa). 
The catalase of the blood of the animals was 
determined before as well as at fixed intervals 
after the introduction of the food materials. 
It was found that the ingestion of the simple 
sugars, dextrose, etc., increased the catalase 
of the blood very quickly and in some cases 
as much as 40 per cent. above the normal. 
SCIENCE 
175 
The starchy foods, flour, etc., increased the 
catalase of the blood, but not so quickly as did 
the simple sugars. The quicker action of the 
simple sugars was attributed to the fact that 
these substances are absorbed immediately 
and taken to the liver, whereas the starchy 
foods had to be digested before absorption. 
Proof that the simple sugars increase the cata- 
lase of the blood by stimulating the digestive 
glands, particularly the liver, to an increased 
output of catalase, is offered in the following 
experiment. After etherizing a dog, the ab- 
dominal wall was opened and the liver ex- 
posed. A comparison was made of the amount 
of catalase in the blood taken directly from 
the liver with the amount of blood coming 
from the tissues, that in the blood of the 
jugular vein, for example. The blood in the 
liver or coming directly from the liver was 
always found to be richer in catalase by 15 
to 20 per cent. than the blood taken from any 
other part of the body. This comparison was 
made in a great number of animals and is 
taken to mean that the liver is continually 
replenishing the catalase of the blood which is 
being continually used up in the oxidative 
processes of the tissues. After introducing a 
simple sugar, such as dextrose, into the ether- 
ized animal with its abdominal wall opened, 
the catalase of the blood taken from the liver 
was increased much more extensively and 
rapidly than the blood from a vein such as 
the jugular. This observation is interpreted 
to mean that after absorption the sugar was 
taken to the liver and stimulated this organ 
to an increased output of catalase. The end 
products of digestion of the other food-stuffs 
were tried in a similar manner and all these 
substances were found to stimulate the liver 
to an increased output of catalase, meat digest 
being most effective, fat next, and sugar least. 
Of the fats both the olive oil and bacon 
produced a very quick and pronounced in- 
crease in the catalase of the blood, whereas the 
cream, lard and butter did not act so quickly, 
due presumably to their slower absorption 
from the alimentary tract. Coffee, milk, cocoa 
and tea did not produce an appreciable in- . 
crease in catalase, while chocolate did. The 
