SAPO MOLLIS. 
744 
of arsenic must be recorded either in the ledger of the wholesale 
dealer, or in the book kept by the retailer for that purpose, in 
accordance with the provisions of the Act. This will afford 
the means of tracing arsenic to the possessor, and will be a 
check upon the criminal, and an inducement to extra caution on 
the part of all persons who buy or sell arsenic. 
Pharmaceutical Journal, June 1851. 
SAPO MOLLIS. 
ALTHOUGH soft soap has been included in the Materia 
Medica of the London Pharmacopoeia since 1836, yet, as it was 
not ordered in any of the formulae contained in that work, and 
is but rarely prescribed, it has not hitherto been generally kept 
in a state fit for medical use by pharmaceutical chemists. In 
the new Pharmacopoeia, which has just been issued, soft soap 
is ordered as a constituent of several of the pill-masses, and it 
will therefore be necessarily kept in future by every one en- 
gaged in dispensing medicines. 
The common soft soap of commerce is not the sapo mollis of 
the Pharmacopoeia. The former is an offensive compound 
made with stinking fish oil or other impure oil, and is wholly 
unfit for use in medicine ; whereas the latter, according to the 
instructions of the College, is prepared from olive oil and potash, 
and is perfectly free from any disagreeable odour. It is ex- 
pressly stated in the new Pharmacopoeia, that common soft soap, 
made with fish oil and potash, is not to be substituted for sapo 
mollis, P.L. 
The demand which will immediately arise for this article will 
ensure a sufficient supply from the wholesale manufacturers; 
yet to some of our readers a few observations with reference to 
the process by which it is made may not be unacceptable. 
The ingredients employed are olive oil and caustic solution of 
potash, which are boiled together, continuing to add the alkali 
until the mixture, which at first has the appearance of an emul- 
sion, becomes gelatinous and perfectly transparent. Excess of 
alkali beyond that which enters into the composition of the soap 
is necessary to produce this effect ; and, in addition to this free 
alkali, the gelatinous mass will also contain more than the proper 
quantity of water, as well as the glycerine, which is one of the 
products of the process. 
The excess of water is driven off by evaporation. In making 
