An ointment of calomel or ammoniated mercury; forty to sixty grains to the ounce.
Strong salicylic-acid ointment; a half to one drachm of salicylic acid to the ounce of lard.
Tar ointment, official strength; or the various tar oils, alone or with alcohol, as a lotion, or in ointment form.
Liquor picis alkalinus[B] is a valuable remedy in chronic thickened, hard and verrucous patches, but is a strong preparation and must be used with caution. It is applied diluted, one part with from eight to thirty-two parts of water; or in ointment, one or two drachms to the ounce. In such cases, also, the following is useful:—
℞ Saponis viridis,
Picis liq.,
Alcoholis, ....................āā................. ʒiij. M.
SIG. To be well rubbed in.
℞ Potassæ ,......................................... ʒj
Picis liq., ...................................... ʒij
Aquæ, ............................................ ʒv.
Dissolve the potash in the water, and gradually add to the tar in a mortar, with thorough stirring.
In similar cases, also, the parts may be thoroughly washed or scrubbed with sapo viridis and hot water until somewhat tender, rinsed off, dried, and a mild ointment applied as a plaster.
Lactic acid, applied with one to ten or more parts of water is also of value in the sclerous and verrucous types. Caustic potash solutions, used cautiously, may also be occasionally employed to advantage in these cases.