342 PROFESSOR LISTER ON THE GERM THEORY 
laid within the last twenty-four hours, was steeped for a while*.in a solution of 
carbolic acid in twenty parts of water, to destroy any organisms adhering to 
the shell, and was then broken in a fine spray of carbolic acid solution of the 
same strength, and about an ounce of the white of the egg was introduced into 
a flask containing ten ounces of water, which had been boiled and allowed to 
cool, the air which entered during cooling having been filtered of dust by a 
mass of cotton wool tied tightly over the mouth of the vessel before boiling. 
The flask was agitated occasionally during the next twenty-four hours, to pro- 
mote diffusion of the albumen in the water, after which the liquid was passed 
through a boiled filter placed in a “ heated” funnel, protected with a “ heated” 
glass cover, under a large glass shade.t It was thus cleared of the shreddy 
residue of the white of egg, and also of the opaque floccules resulting from the 
action of the carbolic acid spray upon the albumen, and was obtained of crystal 
clearness in the ‘‘ heated” flask into which it was received, and in which it was 
kept protected from dust by a “heated” glass cap anda glass shade. A “heated” 
wine-glass, provided with cover and glass shade as usual, being charged with 
some of this liquid, I inoculated it with a little of the toruloid scum from the 
second wine-glass on the 3d September. The result was a corpuscular develop- 
ment of a delicate inconspicuous character, the growth proceeding so slowly 
that the little patch of scum, in which alone any increase was observed, had 
not doubled its diameter in ten days. I now introduced with a “heated” 
needle a little piece of the fungus, in the filamentous form, from the first 
glass of Pasreur’s solution. This retained the filamentous mode of growth in 
the new habitat, but increased so slowly that after the lapse of six weeks the 
little woolly mass which lay at the bottom of the glass had only grown to the 
height of an eighth of an inch, while the patch of scum was but very slightly 
larger than before, and a mere trace of granular deposit was seen upon the 
glass. 
But though the growth of the organism in this medium had been so ex- 
tremely languid, it had effected a very remarkable change in its constitution, the 
liquid, though still clear, having been altered from its original crystal purity to 
a deep rich brown colour, like that of porter. 
It happened that I had inoculated another glass of this same albuminous fluid 
* The actual time was much longer than I had intended, viz., two days. A subsequent experi- 
ment, in which one hour and twenty minutes was the period of immersion, was equally successful. 
Even after the two days of the present occasion, the carbolic acid did not seem to have affected the 
albumen, which was free from coagulation to the surface. 
+ This was a most troublesome procedure to carry out. I afterwards simplified the process very 
much, so as to dispense with both the spray and the filter, extracting the albumen with “ heated” 
pipette passed into a hole made in the carbolised shell with “ heated” forceps, a piece of carbolised 
cotton wool being wrapped round the pipette and egg to prevent entrance of dust, filtration of the 
mixture of albumen and water being effected by decanting through a boiled syphon, which had a piece 
of sponge tied over the end in the flask. 


