Acts powerfully upon the vegetative sphere, affecting more especially the organic substances of the body, and involving prominently mucous surfaces, glandular structures, bones, and joints. The general condition of system produced, representing a perverted nutrition, resembles the two great dyscrasias-scrofula and rachitis-while the action of the drug, like that of the disease, is also slow, deep, and long-lasting. The chief property of Silicea is its power to produce a suppurative process, either in soft tissues, in the periosteum, or in the bone itself. As a secondary result of the morbid processes set up by Silicea , the nervous system becomes involved, giving a condition of erethism conjoined with exhaustion, and resulting in various nervous disorders, spinal irritation, exalted activity of the senses, followed by depression and paralysis. Characteristic symptoms.