98 ORIGIN OF SUGAR IN THE ANIMAL ECONOMY. 
days, and the following is an exact statement of the results 
obtained. The proportion of sugar of milk diminished to 
2-13 per cent, on the third day, 1*97 on the fifth, 189 on the 
sixth, and afterwards oscillated between 1-73 and 1*92 until 
the 21st day. It will thus be observed, that alimentation on 
meat alone diminishes the quantity of sugar in the milk, but 
this principle still exists in it in appreciable proportion. 
Second Experiment. — A full-grown healthy dog was fed for 
13 days upon cooked meat. Inhalations of chloroform were 
used to produce anaesthesia, the abdomen was opened, and 
the blood was collected separately from inferior vena cava 3 
from the hepatic veins, and from the crural artery ; the 
following per centages of sugar were then found in the 
blood : 
Sugar per cent, 
of blood. 
Blood of the crural artery . . . . 0 055 
Blood of the vena cava ..... 0*14:8 
Blood of the hepatic veins .... 0*153 
This experiment, repeated three times, gave analogous 
results. 
Second Question. — Is Sugar produced in the Animal 
Economy by the transformation of Nitrogenous Matters or of Fat? 
For the study of this question I instituted a new series of 
experiments. A dog was fed for ten days upon a mixture of 
beef fat and butter not containing a trace of sugar. Another 
dog was fed for ten days upon the muscular fibre of cooked 
meat, carefully separated from the fat. A third dog was 
kept without any food for ten days. The blood of the vena 
porta, vena cava, and hepatic veins, was collected from these 
three dogs and was found to contain : 
Alimentation. 
Quantity of Sugar per cent, of Blood. 
Of the vena 
porta. 
Of the 
hepatic veins. 
Of the 
vena cava. 
Butter and fat 
Muscular fibre 
Absolute abstinence .... 
yy 
0*146 
0*149 
0*013 
0*130 
0*128 
traces. 
In another experiment, made lately, only traces of sugar 
were found in the blood of the hepatic veins and vena cava. 
On comparing the results of these three experiments we 
are tempted to admit, that the fatty matters concur with the 
