ually almost anything else one uses, short of
illegal or expensive drugs, causes such specimens to distort or
contract into useless lumps. Once the chromate has thoroughly killed
and relaxed them, say after an hour or two, the specimens can be fixed,
preserved, or manipulated as required. You may wish to compare this
method with the method that I describe for killing molluscs with
boiled water.

* One effective way of killing molluscs, particularly gastropods,
snails and the like, whether terrestrial, freshwater or marine, in
fully extended form, is to put them into cool or barely lukewarm,
freshly-boiled water that has been kept closely covered in airtight
containers for cooling without permitting a lot of oxygen to
re-dissolve in the water. First rinse the live specimens in fresh
water to clean away superficial dirt and slime, then submerge them in
the de-oxygenated water. Place some sort of grid or other barrier to
ensure that they cannot get near the surface, and re-seal the
container to keep air out. Leave them for at least twenty-four hours
before transferring them to a preservative fluid or otherwise
proceeding to deal with them. This method leaves them fully extended
and firm, ready for dissection or for preservation for display. If you
remove them too soon, they at first seem dead, but contract say, when
a scalpel stimulates a still-living nerve.

* The cyanide bottle for killing insects certainly could be very
useful, though I am not certain how widely such a dangerous substance
would be available nowadays. Many forms of killing bottle have been
used in the last century or so, and several are described in many
handbooks. An old favourite handbook of mine is the British Museum
Instructions to Collectors (Insects). Most killing bottles depend on
some volatile liquid soaked into plaster, rubber or cotton wool. My
own favourite was ethyl acetate, which is safe, inoffensive, and has
several advantages, as long as the bottle and fluid are kept free from
moisture. For some reason the presence of water seems to reduce its
effectiveness at quickly immobilising specimens. Dry ethyl acetate
paralyses most insects very quickly, even if it takes longer to kill
them. For example, unlike many popular components of killing bottles,
ethyl acetate leaves dead specimens relaxed.

* When you have treated wet specimens with anything acid, do remember
to neutralise the acid residues as soon as possible. The same applies
if you