against the subsequent access of septic material. Thus the use of the spray might be dispensed with, and no one would rejoice more than myself in getting rid of that complication." The suggestion thus indicated was not acted upon in surgical practice till after much testing and experiment, by which Lister was led to conclude, definitely, that it was the grosser forms of septic mischief, rather than microbes in the attenuated condition in which they exist in the atmosphere, that were to be dreaded in surgical practice. At the London Medical Congress, in 1881, he hinted that it might turn out possible to disregard altogether the atmospheric dust, but he still did not venture as yet to try this upon his patients.
At the Berlin Congress, in 1890, he brought forward what he regarded as absolute demonstration of the harmlessness of the atmospheric dust in surgical operations and of the sufficiency of methods in which irritation of the wound by strong antiseptics was avoided.
Under the method now in use, as described by Prof. H. Tillmanns in Nature's "Scientific Worthies," "operations are performed with almost painfully precise sterilization of every object or instrument employed, as Lister first taught us to do, while at the same time we limit as far as possible the action of irritant antiseptics, such as carbolic acid, and even advantageously use none at all, operating with as little fluid as possible. So far as it may be necessary, the fluid now employed is a sterilized solution of common salt, or else sterilized water. In the place, then, of carrying out our operations under the former strictly antiseptic precautions, we now operate aseptically. But the fundamental idea on which Lister's antiseptic method was based has remained unchanged, and will always be the same. . . . The operational area on the patient is carefully disinfected in accordance with Lister's instructions, and is surrounded with aseptic linen compresses sterilized in steam at from 100° to 130° C. We employ exact and definite methods to free our hands from microbes, and the instruments are sterilized by boiling in one-per-cent solution of sodium carbonate. All bandages and the outer garments we wear are made aseptic by prolonged exposure to steam at from 100° to 130° C, in a specially constructed apparatus; and so, also, in respect to all else. Steam thus provides us nowadays with non-irritant bandaging materials free from germs with even greater certainty than did their earliest impregnation with antiseptic substances. . . . Instead of sponges we now use muslin absorbents sterilized by steam, and these, like every other fragment of bandaging material, are burned after being used but once. In short, the technics of modern surgery is based on Lister's method,