This section is from the book "Materia Medica And Therapeutics Inorganic Substances", by Charles D. F. Phillips. Also available from Amazon: Materia medica and therapeutics.
Calcium sulphide exerts a marked influence on the formation of pus. If given early, it controls the inflammatory process, either aborting it so that it does not go on to suppuration, or, if this take place, controlling and limiting its extent, promoting a more healthy formation, quicker evacuation, and more rapid subsequent healing.
In the treatment of simple abscess I have frequently used it with much advantage; in tonsillar abscess (quinsy) it is particularly valuable, and may save recourse to incision; and in mammary abscess, if the time for belladonna or antimony is past, the sulphide is quite the best remedy. It has seemed to me to check the spread of the inflammation, and to help quickly to evacuate matter, and so shorten the tedious course common in this malady. Should hardness and pain continue after an opening has formed, and should the discharge come away incompletely, the remedy must still be continued, and is likely to exert a favorable influence.
In bubo, especially if indolent, and with scanty, unhealthy pus-formation, the sulphide will often determine a more healthy action; 1/4 to 1/2 gr. in pill every three or four hours is a suitable dose.
In ordinary boils, and in carbuncles also, a compress moistened with sulphide of calcium lotion - (4 gr. to the pint of water) - should be applied. When eruptions of boils recur at intervals, I commonly advise a course of the precipitated sulphur - 5 to 10 gr. night and morning - for several weeks during the intervals, but, at the time of actual maturation, recommend the sulphide as acting more quickly. Even in pneumonia, in those exceptional cases when the exudation in later stages degenerates into pus, I have seen benefit from the same remedy; it has equally seemed to assist evacuation of matter already formed, and to check the tendency to its fresh formation.