Cerate, Soap. Syn. Compound soap cerate; Cera′tum sapo′nis (Ph. L. 1836), C. saponis compos′itum (Ph. L. 1851), L. Prep. 1. (Ph. L.) Boil litharge, 15 oz., in distilled vinegar, 1 gall., until dissolved, stirring continually; then add of Castile soap, 10 oz.; again boil until all the moisture is evaporated; then add, gradually, beeswax, 121⁄2 oz., and olive oil, 1 pint, previously melted together, and stir until nearly cold. Similar to Soap cerate plaster (Emplastrum Cerati Saponis), B. P. (which see).
2. (Wholesale.) Distilled vinegar, 6 galls.; litharge, 5 lbs.; soap, 33⁄4 lbs.; yellow wax, 41⁄2 lbs.; olive oil, 6 pints. Mix as above. Good nut or poppy oil may be used instead of olive oil.
Obs. Unless the instructions contained in the above formulæ are followed in every particular, the process is apt to miscarry. When this is the case, the cerate, on cooling, separates into two portions, and is commonly full of hard, gritty particles. To prevent this, care should be taken to use soap of the best quality. This mishap cannot be got over by long boiling and stirring, as is generally supposed. The only remedy is the addition of a little more soap, previously melted with some water, and again evaporating to a proper consistence. A small quantity of solution of potassa has a similar effect.
The colour and consistence of soap cerate chiefly depends on the length of time it is kept heated after the addition of the oil and wax. As evaporation proceeds, so the colour and consistence increase. Its usual colour is that of a lively, pale chocolate-brown, but occasionally it is much paler. This arises from its containing an undue quantity of moisture. When it has been kept heated for a period beyond that usually adopted, it attains greater hardness, and is then frequently called hard soap cerate (Cera′tum saponis durum); but by over-boiling it is apt to become gritty.
Uses, &c. Soap cerate is resolvent, cooling, and desiccative, and is chiefly employed as a cooling dressing for scrofulous swellings, &c. It may be spread on linen and applied like a plaster. It is sometimes used as a support for
fractured limbs, and forms an excellent dressing for soft corns.
Cerate, Spermace′ti. Syn. White cerate, White lip salve, Simple c.; Ceratum sim′plex (Ph. E.), C. album (Ph. L. 1745), C. sperma′tis ce′ti (Ph. L. 1788), C. ceta′cei (Ph. L. 1809, and since), L. Prep. 1. (Ph. L.) Spermaceti, 2 oz.; white wax, 8 oz.; melt by a gentle heat; add, olive oil (warm), 1 pint, and stir with a spatula until they cool.
2. (Ph. E.) See Cerate, Simple.
3. (Ph. D.) The corresponding preparation of the Ph. D. is classed under Ointments, and contains lard.
4. (Commercial.) On the large scale lard or suet is substituted for oil, by which means less wax is required. The following is a good form where a cheap article is wanted, and is that commonly adopted in the wholesale trade:—