RAT POISONS

(See also Turpentine.)

Poisons for rats may be divided into two classes, quick and slow. Potassium cyanide and strychnine belong to the first, and phosphorus and arsenic to the second. Both should be kept away from children, dogs, and cats, and this is best done by putting them in places too narrow for anything larger than a rat to squeeze into. If the poison is too quick, the effect of it is visible to the same rats which saw the cause, and those which have not eaten of the bait will leave it alone. On the other hand, if it is too slow, the poisoned rat may spread it to edible things in the pantry, by vomiting. Slow poisons generally cause the rat to seek water, and when they are used water should not be left about promiscuously.

The substances most useful as rat poisons, and which are without danger to the larger domestic animals, are plaster of Paris and fresh squills. Less dangerous than strychnine and arsenic are the baryta preparations, of which the most valuable is barium carbonate. Like plaster of Paris, this substance, when used for the purpose, must be mixed with sugar and meal, or flour, and as a decoy some strong-smelling cheese should be added. In closed places there should be left vessels containing water easily accessible to the creatures.

One advantage over these substances possessed by the squill is that it is greedily eaten by rats and mice. When it is used, however, the same precaution as to water, noted above, is necessary, a circumstance too frequently forgotten. In preparing the squill for this purpose, by the addition of bacon, or fat meat of any kind, the use of a decoy like cheese is unnecessary, as the fats are sufficiently appetizing to the rodents. It is to be noted that only fresh squills should be used for this purpose, as in keeping the bulb the poisonous principle is destroyed, or, at least, is so modified as to seriously injure its value.

Squill Poisons.

I.—	Hog’s lard	500 grams
	Acid salicylic	5 grams
	Squill	1 bulb
	Beef suet	50 to 100 grams
	Barium carbonate	500 grams
	Solution of ammonium copper acetate, 20 per cent	50 grams

Cut or grate the squill into very small pieces, and fry it in the lard and suet until it has acquired a dark-brown color and {614} the fats have taken up the characteristic squill odor; then to the mess add the other substances, and stir well together.

II.—	Squill, bruised	4 ounces
	Bacon, chopped fine	6 ounces
	Flour or meal, enough.
	Water, enough.

Make into a stiff mass, divide into small cakes, and bake.

Phosphorus Poisons.

To 200 parts of simple syrup, in a strong flask, add 50 parts of phosphorus and 10 parts of talc powder; place the container in a suitable vessel and surround it with water heated to 120° to 130° F., and let it stand until the phosphorus is melted. Now, cork the flask well, tie down the cork, and agitate until the mixture is completely cold. As a measure of precaution, the flask should be wrapped with a cloth.

To make the poison take 50 parts of rye flour and mix with it 10 parts of powdered sugar. To the mixture add about 40 parts of water and from 30 to 40 parts of the phosphorated syrup, and mix the mass thoroughly.

While it is best to make the phosphorated syrup fresh every time that it is required, a stable syrup can be made as follows:

Heat together very carefully in a water bath 5 parts of phosphorus, 3 parts of sublimed sulphur, and 30 parts of water, until the phosphorus is completely melted and taken up; then add 30 parts of wheat flour and 6 parts of ground mustard seed, and work up, with the addition of warm water from time to time, if necessary, into a stiff paste, finally adding and working in from 1 to 2 parts of oil of anise.

Borax in powder, it may be noticed, is also useful as a preservative of phosphorated paste or the electuary.

Mühsam gives the following formula for an electuary of phosphorus for this purpose:

I.—	Phosphorus, granulated	1 part
	Rye flour	30 parts
	Simple syrup	10 parts
	Mustard seed, powdered	1 part
	Sublimed sulphur	1 part
	Water	10 parts

Proceed as indicated above.

Hager’s formula for “Phosphorus globules” is as follows:

II.—	Phosphorus, amorphous	10 parts
	Glycerine	20 parts
	Linseed, powdered	100 parts
	Meat extract	15 parts
	Quark, recently coagulated, quantity sufficient.

Mix, and make a mass, and divide into 200 globules, weighing about 15 grains each. Roll in wheat flour, in which a little powdered sugar has been mixed.

Phosphorus electuary, made as indicated above, may be smeared upon bits of fried bacon, which should be tacked firmly to a bit of board or to the floor. It is essential that either flour or sugar, or both, be strewn over the surface of the phosphorus.

The most convenient in practice, on the whole, are the phosphorus globules, either made after Hager’s formula, or, more readily, by adding rye flour and sugar to the electuary and working up to a pill mass, or barium carbonate and plaster may be added.

Arsenical Poisons.

I.—	Arsenic, white, powdered	100 parts
	Soot from the kitchen	5 parts
	Oil of anise	1 part
	Lard, sufficient.
	Wheat flour, sufficient.
Make into 400 globules.
II.—	Beef suet	500 parts
	Rye flour	500 parts
	Arsenic, white, powdered	50 parts
	Ultramarine	10 parts
	Oil of anise	1 part

Melt the suet, and add to the flour, mix in the other ingredients, and work up while hot, beating the mass with a roller. Make 1,000 globules.

Strychnine Poisons.

Strychnine sulph	1 drachm
Sugar milk	3 drachms
Prussian blue	5 grains
Sugar	¹/₂ ounce
Oat flour	¹/₂ ounce

Nux Vomica Poison.—

Oatmeal	1 pound
Powdered nux vomica	1 ounce
Oil of anise	5 drops
Tincture of asafetida	5 drops

Barium Poison.—

Barium carbonate	4 ounces
Sugar	6 ounces
Oatmeal	6 ounces
Oil of anise	4 drops
Oil of caraway	4 drops

RAZOR PAPER: See Paper.