DISEASES OF THE URINARY ORGANS. 139 
SACCHARINE DIABETES (DIABETES MELLITUS, GLYCOSURIA, OR 
INOSURIA). 
This is primarily a disease of the nervous system or liver rather 
than of the kidneys, yet, as the most prominent symptom is the sweet 
urine, it may be treated here. 
Causes.—Its causes are varied, but resolve themselves largely into 
disorder of the liver or disorder of the brain. One of the most 
prominent functions of the liver is the formation of glycogen, a prin- 
ciple allied to grape sugar, and passing into it by further oxidation 
in the blood. This is a constant function of the liver, but in health the 
resulting sugar is burned up in the circulation and does not appear in 
the urine. On the contrary, when the supply of oxygen is defective, 
as in certain diseases of the lungs, the whole of the sugar does not 
undergo combustion and the excess is excreted by the kidneys. Also 
in certain forms of enlarged liver the quantity of sugar produced is 
more than can be disposed of in the natural way, and it appears in the 
urine. A temporary sweetness of the urine often occurs after a 
hearty meal on starchy feed, but this is due altogether to the super- 
abundant supply of the sugar-forming feed, lasts for a few hours 
only, and has no pathological significance. In many cases of fatal 
glycosuria the liver is found to be enlarged, or at least congested, and 
it is found that the disorder can be produced experimentally by 
agencies which produce an increased circulation through the liver. 
Thus Bernard produced glycosuria by pricking the oblong medulla at 
the base of the brain close to the roots of the pneumogastric nerve, 
which happens to be also the nerve center (vasomotor) which presides 
over the contractions of the minute blood vessels. The pricking and 
irritation of this center leads to congestion of the liver and the exces- 
sive production of sugar. Irritation carried to this point through the 
pheumogastric nerve causes saccharine urine, and, in keeping with 
this, disease of the pancreas has been found in this malady. The com- 
plete removal of the pancreas, however, determines glycosuria, the 
organ having in health an inhibitive action on sugar production by 
the liver. The same result follows the reflection of irritation from 
other sources, as from different ganglia (corpora striata, optic thalami, 
pons, cerebellum, cerebrum) of the brain. Similarly it is induced by 
interruption of the nervous control along the vasomotor tracts, as in 
destruction of the upper or lower cervical sympathetic ganglion, by 
cutting the nervous branch connecting these two, in injury to the 
spinal marrow in the interval between the brain and the second or 
fourth dorsal vertebra, or in disease of the celiac plexus, which 
directly presides over the liver. Certain chemical poisons also cause 
saccharine urine, notably woorara, strychnia, morphia, phosphoric 
acid, alcohol, ether, quinia, chloroform, ammonia, arsenic, and 
phlorizin. 
