The gonococcus (the microbe of gonorrhea) is a pus--producing bacterium, occurring in pairs, resembling in form two coffee grains, generally with a distinct interval of separation. Although its natural habitat is the mucous membrane lining the genito-urinary tracts it may invade the muscular and serous and other tissues. If often affects the Fallopian tubes and ovaries and the serous lining of the pelvic and abdominal cavities. The deeper sub-mucous tissues of the uterus and the male genito-urinary tracts are also frequently involved, it being sometimes impossible to eradicate it from these deeper retreats. From these deeper tissues it is more commonly taken up by the circulation and deposited in distant parts, frequently in the joints. When it becomes thus systematically disseminated, the so-called secondary or metastatic lesions are almost as numerous, though not as virulent, as syphilitic infection. Recent pathological researchers have found that occasionally the gonococcus becomes the causative factor in inflammations of the muscles, tendons, and glands, and in inflammatory conditions of the lungs, kidneys, heart, and even the brain, spinal cord, and the serous membranes enveloping these great cranial and spinal viscera. The individuality and characteristics of the syphilis microbe were not positively determined until in 1905, Schaudinn, of Germany, convinced the medical world that it was a spiral, corkscrew-like organism, from a quarter to one millimeter in thickness, and from four to twelve millimeters in length. It is not so discriminating as the gonococcus in its points of inoculation, nor is it as vulnerable to attack; and it is vastly more destructive to the tissues invaded. It spares no tissue in the human frame, and resists destruction by any known drugs of vegetable origin. When in a latent state its presence was often impossible to determine until, two years after its discovery, a test was worked out by Wasserman, also of Germany, by which diagnosis of the infection may be made,--even in latent form,--as in a hereditary case where no clinical manifestations have yet asserted themselves. There is another valuable blood test worked out by Noguchi. With these two tests we are now able to diagnose the disease, almost absolutely, and follow up the treatment till cure is complete, except in some of the incurable brain and spinal cord cases.