STERILISATION OF APPARATUS. 9 
An efficient steriliser may be made out of a cubical 
biscuit box, but it will not stand much usage unless the 
joints are brazed instead of being soldered: this can be 
done by any tinsmith. It is much better to have the 
the bottom of the box replaced by a sheet of copper, 
and a steriliser made in this way will answer every 
purpose and be fairly durable. A circular hole is cut 
through the centre of the lid and fitted with a cork 
bored so as to admit the thermometer. A false bottom 
or a shelf an inch or so from the bottom will keep the 
articles which are being sterilised from the heated 
surface; the false bottom may be made from a sheet of 
tin two inches longer in one of the sides than the 
bottom of the box. The extremities of the longer sides 
are to be turned down for a length of an inch, and 
several holes cut in the plate. 
Lastly, the kitchen oven may be pressed into service 
if no other steriliser is at hand in an emergency. The 
apparatus to be sterilised is to be placed on a layer of 
cotton-wool on one of the shelves, and the temperature 
is observed by means of the thermometer, which should 
be thrust through the little window which permits of 
the regulation of the temperature. Or the heat may be 
continued until the cotton-wool is singed over the whole 
of the exposed surface. This method is very convenient 
for practitioners sending materials to a laboratory for 
bacteriological examination. 
A gas oven is even more convenient, as the tempera- 
ture can be regulated to a nicety. 
All glass apparatus must be thoroughly cleansed and 
dried before sterilisation. The remaining steps differ 
Somewhat in the different cases. 
Flasks are plugged lightly with cotton-wool before 
being placed in the steriliser. Bottles may be sterilised 
