This section is from the book "Camping And Woodcraft", by Horace Kephart. Also available from Amazon: Camping and Woodcraft.
It is easy to make excellent gun oil from the fat of almost any animal. Never use a vegetable oil on a firearm—it is sure to gum. Rattlesnake oil has more body than almost any other animal oil; but that of woodchucks, squirrels, 'coons, etc., is good. A fine oil can also be made from the fat of the ruffed grouse, or from the marrow of a deer's leg bones. Put the fat on a board and with a sharp knife cut it up fine; then put it out in the hot sunlight, or warm it gently (do not let it get hot) before the fire; now force the oil through a strong cloth bag by squeezing it. To clarify it so that it will never become viscid, put it in a bottle with a charge of shot, or some shavings of lead, and stand the bottle where the sun's rays will strike it. A heavy deposit will fall. Repeat, and you will then have an oil equal to that of watchmakers, but with enough body to stay where it is put, rather than running down into the chamber of the gun so as to leave unprotected spots in the barrel. A large squirrel will yield over an ounce of tried oil, a fat woodchuck nearly a pint, and a bear several gallons—eight gallons of grease have been procured from a big grizzly.
Bear's oil, by the way, is better than lard for shortening biscuit and for frying, and, when mixed with sugar and spread on bread, is not a bad substitute for butter and sirup. It is rendered by cooking in a pot hung high over a slow fire, so as not to scorch the fat, which would give off an acrid smell and make the oil less bland. No salt is added; the oil will keep sweet without it, unless in very hot weather (when it should be kept in a cool room, or in a spring, or in a pot sunk in the earth). The Indians, who were very fond of bear's grease, used to preserve it so that it would not turn rancid even when they were traveling in summer, by adding the inner bark of the slippery elm (one drachm to a pound of grease), keeping them heated together for a few minutes, and then straining off. They also used sassafras bark and wild cinnamon for the same purpose. Bear's oil is superior to olive oil for the table, and can be used with impunity by people whose stomachs will not endure pork fat. I happened to be rendering some bear's grease at the time of this writing. The yield was a gallon of oil to ten pounds of fat.
Rattlesnake oil is solemnly regarded by the old-fashioned Pennsylvania DutclL, and by many backwoods folk, as a specific for rheumatism, ringworm, sties, sore eyes generally, and even for hydrophobia! A large fat snake yields from two to two and a half ounces of oil. A piece of muslin is stretched over a glass jar, and the fat, which resembles that of a chicken, is spread on this. The hot summer sun renders it, and the muslin strains it. The Dutch are reported to have a curious way of telling whether the snake has bitten itself and thereby poisoned its fat. They drop a little of the oil into a glass of milk. If the oil floats as a film on top it is good; but if it separates into small beads and the milk gathers in thick white flakes, as though soured, it is a sign that the snake bit itself.
While I am on the subject of animal fats and oils, I may as well say something about extemporized lights for a fixed camp that is far in the wilderness. A slush-lamp is made by taking a tin can, half filling it with sand or earth, sticking in it a thin rod of pine or other inflammable wood, wrapping around this a strip of soft cotton cloth, and filling the can with melted fat which contains no salt. Grease can be freed trom salt by boiling it in water. This is a much better arrangement than to use a shallow dish (as I have seen done) or a mussel shell, and letting the end of the immersed wick project over one side, where it will drip grease. But such a light, although it was the best that many of our pioneers had in the olden days, is at best a smoky and stinking affair. The estimation in which it is held by those who have had to use it may be judged from the fact that in English-speaking countries it has universally been known as a "slut," except in the Klondike, where they call it a "bitch".
If more light is wanted than one wick will afford, use a square vessel with a wick at each corner. Make snuffers or tweezers, by bending a piece of wire, with which to trim the wicks when they smoke.
A rush-light is made by soaking the pith of rushes in melted tallow. When dry, a length of the rush is then placed in a split stick, or any kind of clip, and lighted.
Wherever deer, elk, or other animals whose fat is tallow, are procurable, there is no excuse but laziness for such vile illumination. Very satisfactory candles can be made by the following process, which is called "dipping." For wicking, use cotton cord loosely unwound, or dry shredded bark. Put your tallow in a kettle with some boiling water. One part of hog's lard to three of tallow may improve the product. A mixture of tallow and beeswax is still better. Scald and skim twice. Lay two poles sidewise and about a foot apart on supports, so that they shall be about as high from the ground as the top of an ordinary chair; cut some sticks about 15 or 18 inches long for candle rods; twist your wicking one way, then double it; slip the loop over the candle rod and twist the other way, making a firm wick; put about six wicks on each rod, a couple of inches apart. Dip a row of wicks into the melted tallow, place the rod across the two long poles, and thus dip each row of wicks in turn. Each will have time to cool and harden between the dips. If allowed to cool too fast they will crack: so work slowly. When the first dipping has hardened, repeat the process, and so on until the candles are of desired thickness. Replenish the tallow as needed, taking it off the fire, of course, for each dip. This is the way our foremothers made candles before they got candle molds.
For a candlestick, split the end of a stick for several inches, then again crosswise; open these segments by pushing a flat, thin stick down each; insert candle, and remove wedges; sharpen the other end of the stick, and jab it into the ground whereever wanted. Or, put a loop of bark in the cleft end of a stick, the loop projecting at one side. Or, cut the end of a large potato square off, and gouge a hole for the candle in the opposite end. Other makeshifts are to mold clay around butt of candle, with flat base; bore a hole in a block of wood, or drive three nails in it; use a hollow bone; or, if you want a candlestick attacned like a bracket to a vertical pole, take a pocket-knife with blade at each end, drive one blade into pole so that knife sticks out at right angle, open the other blade half way, on top, and stick candle on it.
 
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