Cantharides is used for this purpose, either as a plaster or in liquid form; that is, in the form of vesicating collodion. Its most frequent use is as a plaster, rarely over one and a half inches square. Scrub the parts well with soap and water, and dry and rub with a soft cloth until the skin is red, then apply the plaster and bandage lightly, so there may be plenty of room for the formation of the blister. Vesication is produced generally within four to eight hours; if it is not, the plaster should be removed and the operation completed by applying a poultice. Great care should be exercised when blistering patients suffering from kidney affections. Cantharides is an acute irritant, and not infrequently causes strangury or acute nephritis. When the cantharidal collodion is used the space to be covered is outlined with oil to prevent spreading; the collodion is applied with a camel’s hair brush or other applicator, and covered with a layer of soft lint and oil silk. _Dressing the Blister._—Puncture the lower part of the bleb; absorb the fluid with a piece of soft cotton; anoint with pure vaselin, and apply a soft dressing. Bandage lightly. Sometimes it is desirable to have the fluid reabsorbed into the system, in which case precautions must be taken to prevent the blister from rupturing. APPLICATIONS FOR PEDICULOSIS (LICE). 1. Pulverized larkspur seed, ℥j (30 gm.); 2. Pulverized sabadilla seed, ℥j (30 gm.); Boiling water, Oj (500 c.c.). One application of these infusions is usually sufficient. 3. Kerosene oil is a cheap and excellent application; it also removes dandruff: Rub lightly upon the scalp for one or two nights and follow in the morning by a shampoo of soap and water. To destroy the nits apply hot vinegar every other day. 4. Wash hair and scalp thoroughly with a good soap, then saturate hair with hot vinegar and tie up securely. Repeat for a few days. HAIR TONICS. 1. Resorcin, gr. xlviij (3 gm.); Glycerin, fʒij (8 c.c.); Alcohol (50 per cent.), f℥ij (60 c.c.). Rub into the scalp each night. 2. Tincture of cantharides, fʒij (8 c.c.); Tincture of nux vomica, f℥ss (15 c.c.); Tincture of capsicum, fʒj (4 c.c.); Bay rum, f℥ij (60 c.c.). Rub into the scalp at night. 3. Tincture of cantharides, fʒij (8 c.c.); Quinin bisulphate, gr. xx (1.3 gm.); Bay rum, f℥iv (120 c.c.); Rain-water or distilled water, f℥iv (120 c.c.). Rub into the scalp each night. FOR MATTED HAIR. Use white vaselin freely each day. Untangle the ends and work gradually toward the scalp. THERMOMETRY. In the _Fahrenheit_ scale there are 180 degrees between the melting-point of ice and the boiling-point of water. In the _Centigrade_ scale there are 100 degrees between the freezing and boiling point of water.