390 Dr. H. Charlton Bastian on the Origin 
communication, however, these investigators stated * that in 
their experiments with potatoes and beetroot, while alcohol 
and carbonic acid were produced in the same way as with the 
fruits, and the alcoholic ferment was absent as before, Bacteria 
of different sizes were invariably found in the acid fluid which 
impregnated the softened tissues of the vegetables in question. 
No details on this point were given, and the authors do not 
appear to have made any further observations on the subject ; 
nor did Pasteur offer any reply to such statements, though he 
had, about this time, been working at the subject himself f. 
Having determined to endeavour to obtain some more 
definite information as to the appearance of Bacteria in this 
way, I have, during the last two or three years, made various 
experiments in which, after small Potatoes had been carefully 
washed they were allowed to soak for a time in different 
germicidal fluids. First of all I employed a solution of 
mercury bichloride (1: 2000); while later, after the pre- 
liminary washing, the potato was allowed to soak in a 5 per 
cent. formalin solution. The screw-top bottle in which the 
potato was placed was also thoroughly washed out with one 
or other of these fluids. In these cases organisms were found 
within, but also after a time on the surface of, the potatoes 
thus treated; so that these particular experiments and 
methods were rejected as not yielding trustworthy results. © 
This was necessary because at a rather earlier date Pasteur 
had stated { that in experiments which he had made with 
many fruits no ferment-organisms ever appeared. He 
declared again that the tissues of healthy fruits and vegetables 
were germless, but intimated that unless care was taken they 
might make their way in from without. 
Subsequently I used a stronger solution of formalin, and 
have never since found organisms on or near the surface, 
though they have often been found within cells in the central 
portions of the potato. I will now, therefore, give brief 
details of some of these experiments. 
In July, 1901, after well washing a small new potato it 
was allowed to soak in a 10 per cent. solution of formalin for 
ten minutes, in a small screw-top bottle, and during this time 
the fluid was frequently shaken so as to cover the whole inner 
surface of the bottle. At the expiration of the time named 
the top was unscrewed, the fluid poured out, and the top then 
tightly refixed, leaving the potato itself and the inner surface 
* Compt. Rend. 1874, ii. p. 1006. 
+ Loe. cit. 1872, ii. p. 788. 
+ Tom, eit. pp. 788 & 981-2. 
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