232 PROGRESS OF MICROSCOPICAL SCIENCE. = [“yyunly, Mocroseaptcal 
of the cases, but, on the other hand, there were a certain number of 
failures where it was possible to find no flaw or defect whatever in the 
tin. They might remain good for two or three years, and then from 
some unknown cause they were found to become putrid, which was 
always known by a bulging out of the ends of the tin, caused by the 
generation of gas inside. Wishing to ascertain the microscopic con- 
dition of meats sold as perfectly good, he procured three tins, one of . 
salmon, one of lobster, and one of Jullien’s soup. He opened them, 
and submitted their contents to microscopic examination, and found 
in each of the tins a very great number of the minute living things 
which were met with in solutions, and which he supposed to be capable 
of coming into existence de novo. These living things consisted of 
minute figure-of-eight particles, bacteria-like bodies, and filaments. As 
far as the filaments were concerned, they made no movement, but there 
was no reason to suppose they were dead. With regard to the move- 
ments exhibited by the figure-of-eight particles, there were certain 
Brownian movements supposed to be due to certain physical conditions 
of the fluid itself, and there were other movements which were un- 
mistakably vital, and between these two extremes there were any 
number of conditions. It was quite possible to meet with Bacteria 
which were really living, but which, nevertheless, showed only languid 
movements. It was impossible to draw any sharp line of demarcation. 
They could not say positively when these slow movements existed 
that the thing was living, but, on the other hand, they had no positive 
right to infer that they were not living. Then Professor Huxley 
said,—* Tf, in the present state of science, the alternative is offered to 
us, either germs can stand a greater heat than has been supposed, or 
the molecules of dead matter, for no valid or intelligible reason that 
is assigned, are able to rearrange themselves into living bodies, exactly 
such as can be demonstrated to be frequently produced in another way, 
I cannot understand how choice can be, even for a moment, doubtful.” 
By this, he presumed Professor Huxley meant that if these alterna- 
tives were put, he would decidedly elect to believe that the germs 
could stand the heat to which they had been subjected rather than 
that it was possible for the living things to have been originated de 
novo. Now, his own experiments, at all events, were so simple in their 
nature, that it did not seem to him that there was very much room for 
the possibilities of error suggested by the Professor. Certain flasks 
containing solutions were taken, in some cases of organic, and in 
others of inorganic matter ; they were hermetically sealed by Professor 
Frankland, and then they were exposed to a temperature of from 146° 
to 153° Cent. He supposed that this amount of heat would destroy 
the germs if they were in the flasks, and that the finding of living 
things in the solutions afterwards would be evidence that they were 
produced de novo. He examined the flasks day after day with the 
greatest care, and saw nothing until the expiration of about three weeks, 
when certain cloud-like flocculi appeared in the solution, and after 
about three weeks more there appeared on one of the flocculi a minute 
white speck, which, though small, increased in size day by day; and 
when the flask was opened at the expiration of sixty-five days, the 
