286 ON THE GERM THEORY OF PUTREFACTION 
of continuing the investigation, I took some of the liquid with me, decanting 
a drachm of it with ‘ heated’ pipette into a ‘ heated’ test-tube about five inches 
long, which I covered with an inverted test-tube of about the same length (of 
course also ‘ heated’), and packed the tube vertically in a box with cotton-wool. 
Five days later (on the 28th of December), having prepared some Pasteur’s solu- 
tion in a manner which I hoped would ensure absence of living organisms at the 
outset,! I inoculated about an ounce with half a minim of the urine in the test- 
tube, including some of the white deposit at the bottom. The glass, which was 
of course ‘ heated’, as well as its porcelain cap, was placed under a glass shade 
in a room varying in temperature from about 60° to 70° Fahr. It is necessary 
to state, that before raising the inverted test-tube which covered that containing 
the urine, I carefully wiped the mouth of the former with a rag dipped in a strong 
watery solution of carbolic acid; without this precaution there would have 
been a risk of contamination of the urine-tube with some portion of cotton 
or dust adhering to the covering tube.? The urine still continued quite bright, 
and on examining with the microscope the residue in the pipette after the in- 
oculation, I found it to consist of the oval torula unmixed with anything else. 
Thirty-six hours after the inoculation I found the inside of the glass that 
contained the Pasteur’s solution sprinkled over from top to bottom with a fine 
granular deposit resembling white sand under a pocket-lens, and about a third 
of the surface of the liquid was occupied by a dense white scum which micro- 
scopic examination on the following day showed to consist of oval torula cells, 
* In preparing the liquid I deviated to some extent from Pasteur’s formula, which is 100 parts 
distilled water, 10 parts pure sugar-candy, 1 part tartrate of ammonia, and the ashes of 1 part of yeast. 
I employed lump-sugar instead of sugar-candy, and reduced its proportion by one half, as it seemed to 
me likely to prove somewhat too strong to suit some organisms. Further, as I had not at hand a refer- 
ence to enable me to ascertain how much of the mineral salts Pasteur employed, I used what seemed 
to me about a suitable amount for a fungus to consume, judging from the quantity that I got by in- 
cinerating a certain weight of yeast ; and this, as I afterwards found, was a little more than Pasteur’s 
proportion. My solution, then, had the following composition :— 
Distilled Water. : : : 1 ESOOOISES: 
Lump-Sugar , : : 250 gers. 
Crystallized Tartrate of Ammonia : 50 grs. 
Dry Ash of Yeast ; : : : 5 grs. 
making rather more than half a pint. The liquid was introduced through a ‘ heated’ funnel into a 
‘heated’ Florence flask provided with a ‘ heated’ glass cap, and was boiled and allowed to cool in the 
pure and covered vessel. A better method of procedure will be described in a later part of this com- 
munication. 
* The efficacy of a strong watery solution of carbolic acid for the destruction of minute organisms 
was familiar to me from experience in antiseptic surgery ; and it is also well illustrated by the method 
of obtaining uncontaminated unboiled urine described in the text. The fact is of great value in experi- 
ments on this subject, as it affords a simple and sure mode of purifying portions of apparatus which it 
would be inconvenient or impossible to subject to heat. And the extensive experience which this 
investigation has involved, enables me to state with confidence that wiping a piece of glass with a rag 
moistened with a solution of carbolic acid in twenty parts of water as efficiently destroys adhering 
organisms as heating to redness in a flame. 
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