No. 421.] MUSEUM TECHNIQUE. 57 
fins can be repaired. It is always best to select fishes to be mounted 
at the place of capture, and thus avoid the injuries occasioned by 
fish dealers in frequently throwing fishes from one vessel to another. 
As only one side of the body is exhibited, it should be the better 
one, though as far as possible, for sake of uniformity, the same side 
of each should be presented to the visitor, as in my opinion it does 
not make as good an impression when some fishes are turned to the 
right and others to the left. 
It is advisable to keep the live fish for some time in an aquarium, 
and make a study of its coloration. Then kill the fish in a 10 per 
cent solution of alcohol. 
In using strong alcohol the mucous layer on the fish becomes too much 
hardened and cannot be removed. 
After one half hour or so the mucous layer can be removed by 
means of a brush. Next lay the fish on its side in a shallow vessel, 
the bottom of which is lined with wax, and put on it some stronger 
alcohol. The fins are then spread, and held in position with insect 
needles. The torn fins are mended with fine silver wire, which is 
later removed. After the fish is in its proper position it is hardened 
by the gradual strengthening of the alcohol; the time required for 
this depends on the size of the fish, one of about two pounds’ weight 
requiring about six days to bring the alcohol to 75 per cent. 
In successful cases the form of the body is scarcely changed at 
all, and the eye fills its cavity as when the fish was alive. It is 
well, in case of larger fishes, to inject some alcohol into the vent 
after killing and to close it with cotton. The intestine should first 
be pierced, also the inner muscles of the body, with a fine scalpel, 
that the injected alcohol may fill the body cavity and more easily 
enter the flesh. 
Externally the fish should not be injured in order to make the 
alcohol penetrate more rapidly, since where injured the fish would 
not get dry enough to paint, and injury to the farther side would 
‘interfere with fastening the fish to the gelatin. Should the belly still 
sink to an interfering extent, the proper roundness can finally be 
secured by stuffing it with cotton. 
Later I have used formaldehyde 1:20, which I believe is to be com- 
mended to keep the body shape well. The Sad is first killed in weak Mx 
then hardened in formalin, and later transferred to alcohol f. 
preservation. With the formalin treatment t ‘ales of some e species come 
off too easily. 

