The discharge from either primary or secondary sores is infectious and may convey the disease, so that great care needs to be taken in handling such sores. After an interval of apparent health, lasting perhaps only a few months, but often for a year or two, the tertiary symptoms or “reminders” make their appearance. These take the form of localised swellings, which soon break down, forming deep ulcers, and if untreated, produce extensive destruction of the part involved, with much deformity. _Prophylaxis._—The methods available are now so well known that they need not be discussed in a work of this kind. Mention need merely be made of the fact that in some foreign countries, owing to unhygienic conditions, there is a greater liability to contract the disease by what may be called unusual methods, and therefore every care should be taken to prevent such sources of infection, as, for example, the contaminated seats of closets, etc. _Treatment._—As soon as the disease is recognised, the treatment must be commenced. Local treatment.—Keep the sore perfectly clean by washing it with an antiseptic solution such as chinosol (1 in 1000). Between the washings, dress it with a piece of lint soaked in “black wash,” or dust it with iodoform powder and cover it with a piece of lint smeared with boric ointment. For the sore throat, use an antiseptic gargle (_see_ Ulceration of Throat, p. 244). General treatment.—The patient must be put on a course of mercury at once. Calomel, one grain twice a day, or grey powder, one grain three times a day, must be administered, and continued until skilled advice can be obtained. The effect of the mercury must be carefully watched, and if the patient complains of soreness of the gums, a coppery taste in the mouth and excessive flow of saliva, the dose must be reduced or the administration of the drug stopped until these symptoms have disappeared. If the calomel or grey powder causes looseness of the bowels, five grains of Dover’s powder may be added to each dose. In some cases, the addition of three grains of the iodide of potash to each grain of calomel does good from the very first. For the later symptoms, continue the mercurial treatment, and give at least five grains of the iodide of potassium three times a day. Since the above was written the whole treatment of syphilis has been revolutionized by the introduction of certain organic arsenic compounds as therapeutic agents. Of these the best known is the German salvarsan, represented in this country by kharsivan, the so-called “606.” Treatment with arsenic has now largely replaced the old method with mercury; but it cannot be carried out except by one having medical training, and so need not be further considered. _Tick Fever._