Rubefacients. Substances or agents, which, when applied for a certain time to the skin, occasion a redness and increase of heat without blistering. They act as counter-irritants. Mustard or powdered ginger, made into a paste with water, hartshorn and oil, and ether or alcohol (when their evaporation is prevented), are among this class of remedies.

5082. Counter-irritants

5082.    Counter-irritants. Substances applied to the surface of the body to establish a secondary morbid action, with the view of relieving one already existing. Those best known are blisters, mustard poultices, hartshorn and oil, and liniment of ammonia.

5083. Blistering Tissue

5083.    Blistering Tissue. These blistering compositions are superior to the common cantharides blisters, from their greater cleanliness, efficiency, and case of application, and their being less liable to produce excessive irritation.

5084. Strong Blistering Tissue

5084. Strong Blistering Tissue. Powdered cantharides is exhausted with sulphuric ether by percolation (see No. 41 (To obtain Tinctures by Displacement or Percolation)), and the resulting tincture reduced to the consistence of molasses by distillation ; the extract is then mixed with twice its weight of yellow wax, melted by a very gentle heat, and spread on waxed cloth.

5085. Blistering Tissue

5085.     Blistering Tissue. Digest 3 drachms powdered cantharides in 1 ounce ether for a day or two; decant and add 4 drachms sandarach, 2 drachms mastic, 1/2 drachm turpentine, and 10 or 12 drops oil of lavender; mix and spread as above.

5086. Blistering Tissue

5086.    Blistering Tissue. Mix 2. parts acetic extract of cantharides, and 1 part each of resin cerate and bees'-wax; use as before.

5087. Blistering Plaster

5087.     Blistering Plaster. Infuse 3 drachms powdered cantharides in 4 ounces acetic ether for 8 days; decant and evaporate as in No. 5084; then add 4 drachms resin, and spread on court plaster. •

5088. Management of Blisters

5088. Management of Blisters. Spread the plaster thinly on paper, or linen, and rub over it a few drops of olive oil. In this way the blister acts speedily, and with less irritation than usual.

5089. To Camphorate Blisters

5089. To Camphorate Blisters. M. Deschamps d'Avallon has suggested, when it is desirable to camphorate a blister, it may be readily accomplished by dropping on its surface a few drops of a saturated solution of camphor in chloroform, made by adding 2 parts of the latter to 4 of the former.