PATHOGENESIS OF BLACK STONES

A Study on Mechanism of Polymerization in Black Pigment, and Precipitation of Calcium Carbonate

Abstract

Black stones were analyzed by infrared absorption spectroscopy, and attempts were made at synthesis of black pigment in order to reveal the mechanism of polymerization in black pigment.
Besides, an experimental effort was made to explain the mechanism of precipitation of calcium carbonate in black stone.
The spectra of black pigment in black stones were the same as those of synthetic calcium bilirubinate in position of respective absorption bands, and resembled in general aspect.
The former spectra, however, differed from the latter in the intensity of absorption. From these findings, black pigment was identified as polymers of calcium bilirubinate, and the basic structures of them were identical each other.
Moreover, the black pigment prepared from synthetic calcium bilirubinate in alkaline solution was almost identical with the black pigment in black stones both in general properties and spectroscopic findings. These facts suggest that calcium bilirubinate preserved in alkaline solution for a long time transformed into a high molecular weight polymer, i.e. black pigment.