The unfortunate man who has no hard work to do, who is without even a hobby to occupy him, and has no interest in life but the torpid condition of his liver, is a constant sufferer from insomnia. He should be purged and put on a light plain diet. Alcohol must be forbidden and plenty of exercise must be taken. A tumblerful of hot water is to be taken the first thing in the morning and the last thing at night. _Small-pox._ Very prevalent in the tropics, hence the importance of revaccination before going abroad. Incubation period, twelve days. Rash appears third day. _Rash._—Before the appearance of the typical rash there are occasionally earlier rashes, viz., a diffuse blush covering the whole body, resembling scarlet fever, or a dark purple rash of effused blood beneath the skin of the lower part of the belly, or occasionally in the armpit. The small-pox rash proper consists of small red raised spots which first appear on the face, forehead, and scalp, subsequently coming out over the rest of the body, commencing at the top and working downwards. These spots become prominent, and have a characteristic “shotty” feeling under the finger. On the third day after their appearance a small bleb forms in the centre of each spot; it is transparent at first, but subsequently becomes yellowish, from the formation of matter in its interior. The centre becomes depressed on the sixth day, then the bleb breaks down, and discharges matter. Two or three days later the spot begins to dry up, and ultimately heals under a scab. During the period of most active inflammation the face may be very swollen and sodden. The spots and pustules are not confined to the skin, but may occur on the roof of the mouth and in the throat. _Prophylaxis._—This consists in efficient vaccination, and as travellers may themselves have to carry out the technique of vaccination, it is important they should know something about it. The usual faults in technique are a lack of cleanliness, resulting in sepsis, the use of too strong an antiseptic when cleaning the skin, over-heating of the lancet, needle or scarifier when purifying it, drawing too much blood, which washes away the lymph, exposure of the recently vaccinated area to the hot sun, and charring of the lymph in the capillary tube when sealing. All that is necessary is to clean the part to be vaccinated with soap and water, using a nail-brush, then rub the skin with alcohol, and when the latter dries proceed with the little operation. There should be four incisions, and the total area which will eventually be occupied by the vaccine vesicles should not be less than half a square inch. It may be noted that the vesicle is fully ripe on the seventh day after vaccination. _Treatment._—Isolation, similar to that of scarlet fever. The body may be sponged and vaseline applied if there is much itching. The eyelids and eyes should be frequently washed with weak boric acid solution. _Snake Bite_ (_see_ p. 281). _Sprue._