PERSISTENCE OE PUTREFACTIVE AND INFECTIVE ORGANISMS. 
165 
Examined microscopically on the 2nd of November the yellow-fungus tubes were for 
the most part found swarming with exceedingly small and active Bacteria ; the red- 
fungus tubes also swarmed with Bacteria , some beaded Vibrios being mingled with 
them. In many of the tubes examined galloping monads appeared, attaining an 
astounding development in the black-fungus infusion. Patches of moss-like matter 
would appear here and there in the field of the microscope ; and it was no uncommon 
thing to see from ten to twenty monads nestling and quivering in this “ moss,” and 
darting actively in and out of it. They put me in mind of frogs amid their spawn ; 
and as I looked at them my belief in the animality of the one was almost as strong as 
in that of the other. Almost every patch of spawn-like matter had its colony. In 
some cases hardly any thing but monads was to be seen ; but in others the crowding of 
active Vibrios was so great that the monads wholly retreated from the field. ( 
§ 10. Infusions of Cucumber , Beetroot, &c. 
The fungi having disappeared on the approach of winter, I turned to cucumber 
and beetroot, not expecting that their sterilization would offer any difficulty. Two 
closed chambers were accordingly prepared, left for the proper time in quietness, 
and on the 7th of November were charged, the one with the cucumber- and the other 
with the beetroot-infusion. In a few days the infusions in both chambers broke down, 
first losing their transparency and afterwards loading themselves with fatty scum. 
On the 18th of November twenty-four Cohn’s tubes* were charged with infusions of 
cucumber, beetroot, parsnep, and turnip, six tubes being devoted to each infusion. 
They were placed in a vessel of cold water, raised gradually to the boiling-point, and 
maintained at the boiling temperature for ten minutes. Before their removal from the 
hot liquid they were one and all plugged with cotton-wool. 
On the 30th of November all the infusions were thickly turbid throughout and 
heavily coated with scum. 
From some of the precautions already mentioned it may be inferred that before 
this point of the inquiry had been reached, I had begun to suspect the atmosphere in 
which I worked. Hay of various kinds, both old and new, had been exposed and 
shaken about in the laboratory, the air of which doubtless contained multitudes of 
spores which diffused and insinuated themselves everywhere. So, at all events, I 
reasoned. On the 20th of November, therefore, I had infusions of cucumber, beet- 
root, parsnep, and turnip prepared, far from the laboratory, in one of the highest rooms 
of the Royal Institution, and introduced into four new chambers of three tubes each. 
I deemed the precaution of preparing the infusions and introducing them in the distant 
room sufficient. Accordingly, when the chambers were charged they were carried down, 
and the infusions boiled in the laboratory. 
Two days afterwards the parsnep alone remained clear. This, however, was only a 
* See § 4. 
MDCCCLXXVII. 2 B 
