present in nearly everyone, sick and healthy, malarial or typhoid patient alike; so that rose spots are to be found in nearly all fevers in hot weather. None of these signs can be considered as absolutely diagnostic; all or any of them may be present in typhoid, and all or any of them may be present in malarial remittent. The only really diagnostic marks are tertian or quartan periodicity, amenability to quinine, and, above all, that supplied by the malaria parasite in the blood and the Widal serum test. In all doubtful cases the malaria parasite should be sought for; if it is found, the case has certainly a malarial element, and quinine is indicated. If it is not found, and if quinine has not been administered and several negative examinations of the blood have been made, the case is probably one of pure typhoid. Nevertheless, if the malaria parasite is found, typhoid is not necessarily excluded
No one who is proceeding to the tropics to practise medicine should fail to familiarize himself with the technique for the Widal reaction. In Europe he can fall back on the bacteriologist; in the tropics, as a rule, he cannot do this.
Prognosis and management.— Remittents under suitable treatment we expect to see recover; typhoids too often go the other way. A word of caution may be given as to prognosis and treatment. In forming diagnosis too much weight must not be attached to the presence or absence of diarrhœa; constipation is much more common in tropical typhoid than in the disease in Europe. Diagnosis, therefore, must not be too much influenced by absence of diarrhœa, and the practitioner must not be led by the presence of constipation into giving active purgatives. Purgatives are often of the greatest service in malarial remittent; but if, in consequence of a mistake in diagnosis, it is assumed that a case of typhoid is remittent, and large doses of calomel and other cathartics are administered, the result may be disastrous. If doubt exist about diagnosis, and quinine be given, it will not do a typhoid much harm. It is a good rule, therefore, when in doubt, to give quinine, but to avoid purgatives.
