e kidneys or the
blood-stream. It is easy to see how the diplococci of gonorrhoea may
infect the bladder-membrane by direct extension of the inflammation, and
how the bacilli which are swarming in the neighbouring bowel may find
access to the urethra or bladder when the intervening tissues have been
rendered penetrable by a wound or by inflammation. Sometimes, however,
especially in the female, the germs from the large intestine enter the
bladder by way of the vulva and the urethra.

Any condition leading to disturbance of the function of the bladder,
such as enlargement of the prostate, stricture of the urethra, stone, or
injury, may cause cystitis by preparing the way for bacillary invasion.
The bacilli of tuberculosis and of typhoid fever may set up cystitis by
coming down into the bladder from the kidneys with the urine, or they
reach it by the blood-stream, or invade it by the urethra. Another way
of cystitis being set up is by the introduction of the germs of
suppuration by a catheter or bougie sweeping them in from the urethra;
or the instrument itself may be unsterilized and dirty and so may
introduce them. It used formerly to be thought that wet or cold was
enough to cause inflammation of the bladder, but the probability is that
this acts only by lowering the resistance of the lining membrane of the
bladder, and preparing it for the invasion of the germs which were
merely waiting for an opportunity. In the same way, gout or injury may
lead to the lurking bacilli being enabled to effect their attack. But in
every case disease-germs are the cause of the trouble, and they may be
found in the urine. The first effect of inflammation is to render the
bladder irritable, so that as soon as a few drops of urine have
collected, the individual has intense or uncontrollable desire to
micturate. The effort may be very painful and may be accompanied by
bleeding from the overloaded blood-vessels of the inflamed membrane. In
addition to blood, pus is likely to be found in the urine, which by this
time is alkaline and ammoniacal, and teeming with micro-organisms. As
regards _treatment_, the patient should be at once sent to bed in a warm
room, and should sit several times a day in a very hot hip-bath. When
he has got back to bed, a fomentation under oil-silk, or some other
waterproof material, should be placed over the lower part of the
abdomen. The diet should be milk (diluted with hot or cold water),
barley-water, and bread a