STUDIES ON THE PRECIPITABLE SUBSTANCES OF BACILLI OF THE SALMONELLA GROUP.

Specific precipitable substances rich in carbohydrates, containing very little protein and small amounts of a material apparently of fatty nature, have been prepared from the main serological types of the typhoid-paratyphoid groups. The preparations in their present state of purity do not exhibit very pronounced chemical differences in spite of serological dissimilarity. In this respect the results differ from those observed with the polysaccharides of pneumococci. The specificity of the precipitin reactions of these substances parallels in a general way the so called small flaking agglutination. Attempts to separate different fractions from the active substance serologically by means of precipitation with antibody solutions were on the whole unsuccessful. The differences in resistance to the action of acid and alkali were found to be characteristic for various specific carbohydrates.