11 
28 Shells to Clean. The following instructions respecting 
shells, we have drawn up principally from Captain Brown’s 
Conchologist’s Text Book. They will be found useful. If any 
extraneous matter be attached to shells, first steep them in warm 
water; if too hot, it will greatly injure them, by cracking their 
polished surface in all directions ; then remove as much of the dis- 
figuring material as can safely be done, by cutting and scraping it. 
Afterwards, very much dilute a little muriatic acid, and apply 
it with a camel hair pencil, to the matter required to be removed. 
Let it remain a minute or two; dip the shell in cold water, and 
brush it. If the extraneous matter be not removed, repeat the 
operation, taking care so to regulate the strength of the acid, 
and time of applying it, as not to injure the shell. If there be 
fear that any delicate parts of the shell may receive injury from 
accidental exposure to the acid, such pm ts may be protected by 
a thin coat of melted bees’ wax. When the corrosion has been 
completed, apply a little Florence oil, and polish with flannel 
or a brush. Some use also a little emery or tripoly. 
29 Cement for Shells. Such shells as happen to be perforated 
by insects, or othenvise injured, so as to require the filling up 
of any little cavities, or joining of parts together, may be ad- 
mirably repaired with the following composition. 
Fine Spanish whitening, . . 2 oz. Gum arabic, in powder, .... 2 oz. 
Finest flour, j oz. Ox gall, a teaspoonful. 
Well rub these ingredients together in a mortar, and keep the 
mixture for use. Of this, a paste may be made to fill up holes, 
or a cement of thinner consistence, for joining broken parts. 
When required, add a little hot water to part of it for present 
purpose. If mixed and suffered to harden, it may again be 
softened by hot water, and is equally good. Or, keep the gum 
separately, making a strong mucilage of it, and then mix it in- 
to the other ingredients. The advantage of this method is the 
complete solution of the gum, which, otherwise, will sometimes 
appear as little transparent specks in the cement. 
30 Shells to Repair. Fill up injured parts with the above com- 
position, observing to leave the cement more prominent than 
the adjoining parts of the shell. When it has become dry and 
hard, reduce the cement to the required height, either by the 
use of a knife, graver, or file; taking care to represent the natu- 
ral irregularities of the shell. With water-colour then give 
m 
