470 PATHOGENIC BACTERIA. tains gas-bubbles and is sometimes frothy. Occasionally the patients recover, especially when the infected part is susceptible of amputation, but death is a more common outcome. After death the body begins to swell almost immediately; it may attain twice its normal size and be unrecognizable. Upon palpation a peculiar crepitation can be felt in the subcutaneous tissue nearly everywhere, and the presence of gas in the blood-vessels is easy of demonstration. The gas is inflammable, and as the bub- bles ignite explosive sounds are heard. At the autopsy the gas-bubbles are found in most of the internal organs, sometimes so numerously as to justify the German term " Schaumorganen (frothy-organs). The liver especially is apt to show this frothy con- dition. When the tissues from such a case are hardened and examined microscopically it is found that the bub- bles appear as open spaces in the tissue, the ^borders of which are lined with large numbers of the gas bacillus. There are also clumps of bacilli without gas-bubbles, but surrounded by tissue, whose nuclei show a disposition to fragment or disappear, and whose cells and fibers show signs of disintegration and fatty change. In discussing these changes Ernst1 concluded that they were ante- mortem and due to the irritation caused by the bacillus. The gas-production he regarded as postmortem. In the internal organs the bacillus is usually found in pure culture, but in the wound it is generally mixed with other bacteria. On this account it is difficult to estimate just how much of the damage before death is the result of the activity of the gas bacillus. That gas-production after death has nothing to do with pathogenesis during life is shown by injecting into the ear-vein of a rabbit a liquid culture of the gas bacillus, allowing about five minutes' time for the distribution of the bacilli through- out the circulation, and then killing the rabbit. In a few hours the rabbit will swell and his organs and tissues will be riddled with the gas-bubbles. 1 Virchow's Arckiv, Bd. 133, Heft ii.