4. Saline purgatives. These cause a free secretion of the intestinal juices, and a copious motion, proportionate to the size of the dose, is the result. The principal saline purges are Epsom salts (_i.e._, sulphate of magnesia), Glauber’s salts (_i.e._, sulphate of soda), seidlitz powder, the various forms of fruit salts, and the aperient mineral waters, such as Rubinat, Hunyadi Janos, etc. A saline purgative may be given in the morning, to assist the action of an aperient pill administered the previous night. Saline purgatives are useful, too, in many cases of habitual constipation, and, if necessary, a small dose may be given every morning in a tumbler of warm water. _Quinine._—Quinine is chiefly used for malarial fever, and the urgency of the case must be the guide as to the amount to be administered. It is seldom necessary to give more than ten grains three times a day; at times enormous doses, such as thirty grains three times a day, have been given with advantage, but such doses are rarely necessary, and in the absence of a medical man should never be given. The administration of quinine sometimes causes headache, deafness, delirium, and partial or even complete blindness. In such cases the dose should be reduced or the drug withheld until these symptoms have disappeared. _It has been stated that quinine causes blackwater fever; this, I believe, is absolutely untrue._ I have seen cases of blackwater fever, apparently resulting from the neglect of malarious attacks, which date the commencement of their recovery from the first administration of quinine. Quinine is best given in solution; the nauseous taste can be somewhat disguised by adding chloroform water or essence of ginger or lime juice to the solution. Many men take the drug in a little beer or spirit for the same purpose. Quinine pills are, as a rule, very insoluble, therefore they are not suitable for explorers. Quinine in the form of a tablet, or in a capsule, or wrapped in tissue paper, acts well, but even tablets should be cracked or crushed. Sugar-coated products are inadmissible in the tropics. Sometimes, owing to frequent vomiting or other cause, the quinine administered by the mouth cannot be retained. It must then be given by means of an enema or by injection into the muscles. If the traveller decides to give an intra-muscular injection of quinine, he should only give five grains at a time. The dose should be added to about a teaspoonful of water which should then be boiled and allowed to cool. The amount of water is of little importance so long as enough is used to dissolve the drug, and keep it in solution when the water is cool enough to be injected. The less fluid, however, injected the better. Injections are best made deeply into the muscles of the buttock. This is a method best left to a medical man, as there is danger of injuring the sciatic nerve.