APRIL 11, 1884.] 
there were, on the Talisman, special instruments for 
obtaining water at various depths. It is very impor- 
tant to know the composition of the water in which 
a certain fauna lives, in what proportion (sometimes 
under great pressure) gases are dissolved in it, and 
how much salt it contains. This kind of examina- 
tion had already engaged the attention of the natu- 
SCIENCE. 
453 
levers extending out from the line. When a proper 
length of line had been run out, a ring was slipped 
over the line, and allowed to descend, knocking the 
levers and closing the valves as it went down. With 
each bottle was attached a self-registering thermom- 
eter. The gases contained in the water tend very 
energetically to escape, pressing strongly on the 
—— 
Fie. 11. — Examining the contents of a trawl. 
ralists on the Challenger and on the Blake. During 
the cruise in 1882, made by the Travailleur in the 
Bay of Biscay, on the coasts of Spain and Portugal, 
and in the Mediterranean, water was drawn from 
very great depths. For this purpose, water-bottles, 
consisting of strong metal tubes with valves at both 
ends to allow of a free circulation, were attached to a 
sounding-line at distances of five hundred metres 
apart. ‘The valves were kept open by means of brass 
valves, and closing the mouths more effectively. It 
has often happened, that, wpon opening the valves, a 
jet of water was thrown from the bottle, like Seltzer. 
‘The sampling of water from great depths is, as\has 
been shown, a process which requires considerable 
time. Accordingly an attempt was made, on’ board 
the Talisman, to simplify the work when water,was 
desired, not for the gases which it contained, but in 
order to investigate the germs which it held. The fol- 
