Dr. Bean always directs that the viscera be preserved, to assist in identification, even though it becomes necessary to remove them from large fishes and preserve them in separate jars. When there is no particular reason for their preservation, it is a great advantage to remove them and throw them away. They are—unless of scientific value—an abominable nuisance, and do more to spoil good alcohol than all the rest of the fish.
Fishes that have begun to decompose, and have become offensive, yet are too valuable to throw away, may be disinfected by washing them inside and out with a moderately weak solution of pure carbolic acid and water, or with a solution made by dissolving a tablespoonful of chloride of soda in a pint of water.
For years a very common formula for preservative alcohol has been ninety-five per cent alcohol diluted with one-third of its bulk of water, or, in other words, three parts of alcohol and one of water. If there is any fault to be found with this solution, it is that it is stronger than is really necessary. I have preserved barrels of alcoholic specimens in a solution composed of two parts of proof spirits and one part water, and have never lost a specimen except through leakage. This solution is strong enough to stand considerable deterioration without the loss of its contents.
I have never attempted to collect quantities of alcoholics without an alcoholometer in constant use. This little instrument costs but a trifle, and affords the only reliable means for testing the strength of alcohol. Its use enables the collector to exercise economy in the use of his spirits, and get the maximum benefit from it. Therefore I say, buy an alcoholometer at all hazards, and carry it and a suitable test-glass with your outfit. Test the spirits on your specimens frequently, and you will then run no risks of loss.
Keep a receptacle to use as a receiving and curing tank, into which all fresh specimens are placed, with abundant room for each to undergo the curing process. Every animal contains in its body a heavy percentage of water, which must be, in great measure, replaced by the spirits before the flesh can be preserved from decay. Into the first bath a great quantity of blood and abdominal fluids will be soaked out from the specimen, and it is bound to lose strength rapidly, and also become foul. As long as it remains clean enough to use, keep up its strength by the addition of pure spirits, and in it immerse all specimens until they are thoroughly cured. Give them plenty of room at first, and keep them from settling down to the bottom by putting there a bunch of excelsior, tow, or cloth. While the spirits in a can may be strong enough on top to preserve a specimen, at the bottom, where the animal impurities settle, it may be so weak that anything lying in it would soon spoil. Often the tail of a fish which hangs upright in a jar will spoil while the remainder will be preserved.
After specimens have remained in the receiving-tank for from two to four days, according to size, put them in another receptacle in clean, fresh spirits, still allowing them plenty of room. Finally, when ready to pack up and make a shipment home, wrap each fish separately in a piece of thin, white cotton cloth, just large enough to cover it well, dip it in clean spirits, and without any tying or pinning of the cloths, lay the fishes in your barrel like sardines in a box, as closely as they will lie without being squeezed. Fill the receptacle full of fishes, head it up, and then pour into it all the clean spirits it will hold.
In order to proceed with the second and third methods of preserving fish specimens, it now becomes necessary to describe a process.
How to Skin a Fish.—Of course, no one aspiring to become a collector of fishes will remain in ignorance of the names of the different fins. And, more than that, before he can prepare even the rough skeleton of a fish he must know what its bony structure is like. On the whole, there is a good deal to be learned about methods in collecting fishes, and as a beginning we must learn how to skin a scale fish. The methods with cartilaginous fishes will be considered later.
The principles with all scale fishes are precisely the same, the only difference being in the greater amount of cold steel and energy required for such great, hulking brutes as the jewfish, and the magnificent tarpon. For convenience we will take a specimen about a foot in length; for example, a striped bass, a pike, or a red snapper.
As is the case with quadrupeds, the left side of a mounted fish is always expected to be "the show side." Lay the specimen upon its left side, start at the vent with a stout pair of sharp-pointed scissors, and divide the skin in a perfectly straight line along the median line of the belly toward the head, stopping the cut when you approach close to the narrow, tongue-like point which terminates between the lower angles of the gill openings. Now reverse the fish, begin again at the vent, and divide the skin with a clean cut through the scales, in a line parallel with the base of the anal fin, and about half an inch from where the scales meet the fin rays. This is really a cut along the side of the fish, as low down as possible, made necessary by reason of the anal fin. Continue this cut straight back to the tail, as shown in the dotted line g-h in Plate IV.