This section is from the book "The Home Hand-Book of Domestic Hygiene and Rational Medicine. Volume 2.", by J. H. Kellogg, M.D.. Also available from Amazon: The Home Hand-Book of Domestic Hygiene and Rational Medicine, Volume 2.
In these cases, the abscess forms in the mass of fat in which the kidney is embedded, instead of in the organ itself. The abscess may discharge internally or externally. When it discharges internally, it sometimes opens into the intestines and sometimes into the abdominal cavity. In the latter case, the result is speedy death. When it opens externally, or into the intestinal canal, there is a fair chance of recovery.
When a tumor can be felt over the region of the kidney, at the back, which gives evidence of containing pus, it should be promptly opened, to prevent its discharging internally. Fomentations, should be applied to the affected part, both before and after opening the abscess.