NOTES AND QUERIES. 299 
mycelium. Then, again, starch solution is not easy to keep for 
any length of time. Chemists have, it is true. succeeded somewhat 
by the application of salt, chloride of calcium, and other anti- 
septics ; but these more or less interfere with the universal applica- 
tion of starch solution, and could not be used at all with either 
Pasteur’s or Raulin’s fluid. 
Two years ago, the writer devised a plan for keeping such fluids 
as are above-mentioned, and with the result that the remainder of 
a litre of Raulin’s fluid made up in November, 1878, is now as 
good as when first mixed. The illustration, Fig. 62, shows the 
construction of the apparatus :— 
It consists of an ordinary glass flask, 
fitted with an indiarubber stopper 
pierced with two holes, into one of 
which is tightly inserted a tube, packed 
with clean cotton wool. Into the 
other hole, the shorter limb of a glass 
syphon is inserted, the longer limb 
being closed with a spring clip upon a 
short length of rubber-tubing, in ad- 
vance of which is a narrow glass jet, as 
shown in the figure. To put the 
apparatus in working order, nearly fill 
the flask with the fluid, and take out 
the cotton wool from the tube above, 
place over a lamp to boil, and while 
boiling open the clip and stop up the 
open end of the wool tube, so that the 
pressure may drive some of the liquid 
out of the flask. Return this ejected 
fluid to the flask, and keep boiling for 
five minutes, allowing the steam to 
escape from the open wool-tube. 7 
While steam is thus escaping, place Bip. 62: 
a plug about half an inch in depth of 
cotton wool, and allow the steam to blow well through it. After 
one minute plug the whole of the tube with cotton wool, and 
withdraw the flame. By simply opening the clip a supply may now 
be withdrawn, without the introduction of any atmospheric germs 
into the flask. 
