ASEPSIS AND ANTISEPSIS. 
637 
aqueous solutions are used. It is much used also in the, strength 
of i-iooo or 1-2000 for the disinfection of the skin in regions 
that are to be operated upon, and for the disinfection of the 
hands of surgeons and assistants. 
Iodine and Iodoform .—The antiseptic properties of iodine 
are manifold greater than those of carbolic acid—as a bacteri¬ 
cide five times, and as a restrainer of bacterial growth eight 
times as great—but it has attracted general attention only since 
the introduction into use, as an antiseptic, of its compound, 
iodoform. Iodoform did not irritate the wound ; it was used 
both as an application to the wound-surfaces and as an external 
antiseptic, protective dressing; its decomposition or its volatili¬ 
zation was so slow that the frequency of the dressings required 
was greatly lessened. The odor and the toxic qualities of the drug 
were the chief disadvantages that limited its use. It diminishes 
secretion, decomposes ptomaines and stimulates leucocytosis, 
and when itself decomposed liberates the germicidal iodine. 
Aristol, airol, iodol and nosophen are among the other iodine 
compounds used as substitutes for iodoform. 
Salts of Bismuth .—Bismuth subnitrate and bismuth subgal- 
late are of value especially when used as a powder to be dusted 
over the skin surrounding a wound, to restrain the activity of 
epidermal organisms, and as a powder applied to gianulating 
surfaces to promote its cicatrization. 
Salts of Zinc .—Zinc oxide is especially worthy of mention 
and commendation as a dusting powder in the tieatment of 
burns, excoriations and abrasions, and for use upon the skin 
about a wound and along a suture line. It lestiains the aeti\ it) 
of the epidermal organisms. It is of itself peifectly uniriitat- 
ing, and with serous secretions forms a bland and soft magma. 
A mixture of equal parts of zinc oxide and of water, with the 
addition of io per cent, of zinc chloride, forms a paste which, 
when applied to wounds, rapidly dries into a firm piotectixe 
crust or artificial scab. 
Zinc chloride is very soluble in water and in the stronger 
solutions is perfectly caustic. A Strength of 1-50 is required to 
