Acts upon the mucous tissues and the glands, its action closely resembling that of Mercury, and involving the same character of disorganization of fluids and destruction of tissues. The action upon the lymphatic and glandular system is also very similar to that of Iodine, producing hypertrophy and loss of function. It produces thickening of the periosteum, and for this reason is often beneficial in syphilitic nodes. It is said to be the best known antidote for all the bad effects of Mercury, and for secondary and tertiary syphilis. Characteristic symptoms.