2716. 
over the whole country, cholera infection is spread. 
But all reported cases have, as yet, failed of corrobora- 
tion. Nevertheless, the evidence of the facts pro- 
duc2zd cannot be weakened by the failure of the 
experiments on animals. With other infectious dis- 
eases, the same observation has been made; for ex- 
ample, in the case of typhoid fever and leprosy, — 
two diseases for which specific bacteria are known, 
without, as yet, its being possible to communicate 
them to animals; and yet the manner of the occur- 
rence of the bacteria in these diseases is such, that, 
without doubt, they must be looked upon as the 
cause of the disease. The same holds true for the 
cholera bacteria. Moreover, the further study of 
the cholera bacteria has made known many of their 
peculiarities, which all agree with that which is 
known of cholera etiology, as well as further evi- 
dence of the correctness of the assumption of the 
bacteria as the cause of the disease. 
In this connection it is well to state the often 
observed fact, that in the linen of cholera patients 
the bacteria increase in a most remarkable manner, 
when the clothes have been soiled with the evacua- 
tions, and then, for twenty-four hours, have been 
kept in a moist condition. This explains the known 
fact, that the people having to do with such affected 
linen are often attacked. On account of this, 
further experiments were instituted; and cholera 
evacuations, or the contents of the intestines of 
the dead, were spread on cotton, on paper, and 
especially on the damp surface of the ground. After 
twenty-four hours, the thin sheet of slime invariably 
changed into a thick mass of cholera bacilli. 
Another peculiarity of the cholera bacteria is, that 
they die, upon drying, much more quickly than most 
others. Commonly all life is extinct after three 
hours’ drying. 
It has also been noticed that their development 
only takes place well in substances having an alka- 
line reaction. A very small amount of free acid, 
which would have little or no effect on other bacteria, 
puts a marked check on their growth. 
In a healthy stomach they are destroyed, which is 
shown by the fact that neither in the stomach nor the 
intestines of animals which had been constantly fed 
on cholera bacilli, and then killed, were any found. 
This last peculiarity, together with the impossibility 
of their withstanding drying, gives an explanation of 
the every-day observation, that infection so seldom 
occurs from constant intercourse with cholera pa- 
tients. Evidently, that the bacilli may be in condi- 
tion to pass the stomach, and bring about the cholera 
in the intestines, peculiar conditions must be present. 
Perhaps, when the digestion is imperfect, the bacilli 
might be able to pass the stomach; and the fact ob- 
served in all cholera epidemics and in India, that 
those suffering from indigestion are especially sub- 
ject to cholera, may bear out this view. Perhaps a 
peculiar condition, analogous to the period of inac- 
tion of other bacteria, would enable them to pass the 
stomach uninjured. 
It is, on the whole, not probable that this change 
in the production of inactive spores exists: then such 
SCIENCE. 
|Vou. ILL, No. 66. 
spores, by observation, are known to remain months, — 
or even years, capable of life, while the cholera poi- 
son remains active not longer than from three to 
four weeks. Neverthelass, it is conceivable that some 
other form of inactivity exists, in which the bacilli 
can retain their life in a dry state some weeks, and in 
which they withstand the destroying influence of the 
stomach. 
The conversion into such a condition would cor- 
respond with that which Pettenkofer has designated 
as ripening of the ‘cholera-infection material.’ As 
yet, such an inactivity of cholera bacilli has not been 
discovered. 
THE EXPLORING VOYAGE (OF 
CHALLENGER. 
(first notice.) 
Tue Challenger was a British man-of-war, a 
corvette of twenty-three hundred tons, equipped 
at the public expense with every appliance for 
the scientific study of the sea and of marine 
life, and carrying a faculty of six civilian spe- 
cialists chosen by the Royal society, in addi- 
tion to a staff of naval officers selected with 
reference to their scientific attainments. 
This floating laboratory was sent out in 1872 
upon a voyage of discovery around the world, 
and, during an absence of three years and a 
half, visited every accessible sea and ocean, 
traversing a distance of nearly sixty-nine thou- 
sand miles. Three hundred and sixty-two 
observing-stations were established at sea, 
and over five hundred deep-sea soundings 
made, —a wonderful record of industry, when 
it is remembered how many weeks were neces- 
sarily spent at coaling-stations, and when we 
take into account the fact that the present 
methods of rapid work by means of thin-wire 
dredge-ropes had not then come into use, and 
that a dredge-haul from a depth of two thou- 
sand to twenty-five hundred fathoms, which the 
Blake or the Albatross now easily completes in 
four or five hours, took an entire day of the 
Challenger’s time. 
The collections, when finally assembled at 
Sheerness, after the return of the ship, were 
contained in 2,270 jars, 1,749 bottles, 1,860 
glass tubes, and 176 tin cases of alcoholics, 
with 22 casks of specimens in brine, and 180 
tin cases of dried specimens, besides large 
quantities of material already sent home from 
Bermuda, Halifax, Capetown, Sydney, Hong 
Kong, and Japan. 
The Challenger long ago resumed her bar- 
baric function as an engine of war. 
in South Kensington. Their share in the work 
Her trawls 
and dredges, battered and torn, hangupon the 
stair-rails in the Museum of naval architecture — 
