350 Professor Tyndall on Germs. [June, 
which there are no house connections whatever with the street 
sewers, and consequently no water-closets. To this day, there- 
fore, all the excrementitious and other refuse of the inhabitants 
is collected in pails or pans, and remains in their midst generally 
in a partitioned-off corner of the living-room until the next day, 
when it is taken down to the streets and emptied into the cor- 
poration carts. Drunken and vicious though the population be, 
herded together like sheep, and with the filth collected and kept 
for twenty-four hours in their very midst, it is a remarkable fact 
that typhoid fever and diphtheria are simply unknown in these 
wretched hovels.’ 
« This case has its analogue in the following experiment, which 
is representative of a class. On November 30th a quantity of 
animal refuse, embracing beef, fish, rabbit, hare, was placed in 
two large test-tubes opening into a protecting chamber contain- 
ing six tubes. On December 13th, when the refuse was in a 
state of noisome putrefaction, infusions of whiting, turnip, beef, 
and mutton were placed in the other four tubes. They were 
boiled and abandoned to the action of the foul “sewer gas” 
emitted by their two putrid companions. On Christmas Day the 
four infusions were limpid. The end of the pipette was then — 
dipped into one of the putrid tubes, and a quantity of matter 
comparable in smallness to the pock-lymph held on the point of 
a lancet was transferred to the turnip. Its clearness was not 
sensibly affected at the time; but on the 26th it was turbid 
throughout. On the 27th, a speck from the infected turnip was 
transferred to the whiting; on the 28th, disease had taken entire 
possession of the whiting. To the present hour the beef and 
mutton tubes remain as limpid as distilled water. Just as in the 
case of the living men and women in Edinburgh, no amount of 
fetid gas had the power of propagating the plague as long as the 
organisms which constitute the true contagium did not gain ac- 
cess to the infusions. : 
“The universal prevalence of the germinal matter of bacteria m 
water has been demonstrated with the utmost evidence by the 
experiments of Dr. Burdon Sanderson. But the germs in water 
are in a very different condition, as regards readiness for devel- 
opment, from those in air. In water they are thoroughly wet 
and ready, under the proper conditions, to pass rapidly into the 
finished organism. In air they are more or less desiccated, and 
require a period of preparation more or less long to bring them 
up to the starting-point of the water-germs. The rapidity of 
