3
invariably, present ; that its quantity was seldom great, never more than one-fifth of the volume ;
that the urine was almost invariably acid, occasionally neutral, but never alkaline ; and that sugar
was present in large amount in the majority.
The urine of stock rabbits dying from other causes was seldom procurable in such large
quantities, it was usually lighter in colour and more turbid ; it was generally alkaline or neutral;
- and rarely acid, it sometimes contained albumen but never sugar. As the stock animals often
died of coccidiosis of the liver or ulcerative colitis or some other acute infection the frequency
of albumen in their urine is not surprising, but death from such causes could not be confused.
with rabies.
The urine of healthy herbivora is generally somewhat turbid, owing to earthy carbonates
which dissolve on the addition of an acid, and alkaline or neutral, never acid, hence the acid urine
of fixed. virus rabbits is usually clear. It does not contain albumen or sugar.
Further analysis of the urine of several of the passage rabbits showed that the coagulable
proteid consisted almost entirely of serum globulins precipitable by saturation with magnesium
sulphate.
In a few there was also a trace of serum albumen precipitable by boiling after the removal of
the globulins.
The amount of globulin precipitable by different degrees of saturation with ammonium
sulphate varied. considerably. In one instance 21 per cent. saturation gave a considerable
precipitate, and after filtration 30 per cent. saturation gave only a faint cloud, and 50 per cent.
saturation gave another considerable precipitate. In three other instances 21 per cent. saturation
gave only a faint cloud, 30 per cent. saturation gave another faint cloud and 50 per cent. satura-
tion gave a heavy precipitate. In no instance was any one form of globulin present without at
least some trace of each of the others.
It may be concluded that the presence of albumen or globulins in the urine of a rabbit is not
necessarily an indication of rabies as these substances may be found in many other conditions of
diseases. If, however, albumen or globulin are found in a clear, acid urine which also contains a
large quantity of sugar, the presumption is that the animal has died of rabies.
The absence of sugar, though this is seemingly very unusual, does net on the other hand
exclude rabies.
The kidneys of all these passage rabbits were deeply congested, so that the pyramidal and
cortical areas frequently appeared of a uniform tint. Sections showed that there was great
destruction of the cells of the convoluted tubules ; the glomeruli and collecting tubules were little
changed.
No opportunity has yet occurred to us of examining the urine of animals naturally infected
by street virus, but albumen, sugar and even blood have been reported (1) in the urine of human
beings suffering from hydrophobia.
The importance of glycosuria in the diagnosis of rabies in herbivora has also been drawn
attention to by Rabieux and • Nicholas (7), but not having been able to refer to their paper we
do not know to what length they carried their researches.
Distention of the bladder is almost invariably met with in rabbits dying from rabies, but the
phenomenon does not seem to be nearly as common in guinea-pigs, rats or dogs. Nor is the
presence of sugar so usual in the three latter animals even when sufficient urine can be collected for
examination.
The presence of albumen in the urine of rabid animals is consequent on the condition of the
kidneys, but whether the congestion is simply due to va so-motor paralysis or to the attempted
elimination of some toxin is still unknown.
As for the sugar, it may be due to the direct irritation of the glycosuric centre in the floor of
the fourth ventricle or to interference with the function of the pancreas, which has been shown to
be infective in .a certain percentage ; or it is possible that the powers of assimilation are reduced
by the inability of the animal to eat after the onset of motor paralysis, and that the blood becomes
overloaded with sugar which then finds its way into the urine. The stomach and upper gut of
rabbits dying from rabies are often laden with carbohydrate material, even when they have not
eaten for 48 hours or more. The blood of such animals contains a quantity of sugar which we
found easy to demonstrate by the following simple method. Collect about 2 cc of blood from
the heart of the dead animal, which is always engorged, shake it up in a test tube with 3 or 4 cc
of water or salt solution, boil, filter off the coagulated albumen and test the clear filtrate in the
ordinary way with Fehling's solution. There may not always be enough sugar to produce a thick
precipitate, but if the tube be allowed to stand for 5 minutes and cool a small quantity of the
characteristic, yellowish, cuprous oxide will be found at its bottom.
As a diagnostic test the presence of sugar in the urine seems to fail most,frequently in the
case of rabbits which show definite symptoms of rabies after the usual period of incubation and
then die from some cause within 18 hours or so. Of two rabbits inoculated on the same day,
which both showed definite symptoms of rabies on the 6th day and died about 18 hours later, the
urine of one was loaded with sugar while that of the other contained none.