CERUSE, or CERUSS, white lead, a sort of calx of lead, made by exposing plates of that metal to the vapour of vinegar.
The best way of preparing it is the following: A glass-cucurbit is to be cut off in such a manner as to leave it a very long mouth; an alembic head of glass is to be fitted to this; some vinegar is to be put into the body, and a number of thin plates of lead are to be placed in the head in such a manner that they may stand somewhat erect: when the head is fitted on, the body is to be set in a gentle sand-heat for twelve hours; then unaluting the vessels, the receiver, which had been
fitted to the nose of the head, will contain a sweet and styptic liquor, nauseous and turbid, called the vinegar of lead, or the solution of lead; and the plates of lead, taken out of the head, will be found covered with a white dusty matter; this is cerus; and if the operation be repeated, the whole lead will be in fine reduced to this state of cerus.
Cerus is used externally either mixed in ointments, or by sprinkling it on old bleeding and watery ulcers, and in many diseases of the skin. If, when it is reduced into a fine powder, it is received in with the breath in inspiration, and carried down into the lungs, it causes terrible asthma, that are almost incurable, and at last generally prove fatal: sad instances of the very pernicious effects of this metal are too often seen among those persons who work lead in any form, but particularly among the workers in white-lead.
The painters use it in great quantities, and, that it may be afforded cheap to them, it is generally adulterated with common whiting: the English and Dutch cerus are very bad in this respect: the Venetian ought always to be used by apothecaries.