2. If 5 oz. of nitre, and 5 of sal-ammoniac (both finely powdered) be dissolved in 19 oz. of water, the heat of the liquid will be reduced 40 degrees.
3. If 3 lbs. of snow be added to 1 lb. of salt, the mixture will fall to 0° (or 32 degrees below freezing point).
The two following are the coldest mixtures yet known:—
1. Mix 3 lbs. of muriate of lime with 1 lb. of snow.
2. Mix 5 lbs. of diluted sulphuric acid with 4 lbs. of snow.
Q. Why is it more easy to swim in the sea than in a river?
A. Because the specific gravity of salt water is greater than that of fresh, and therefore it buoys up the swimmer better.
Q. How do cooks ascertain if their brine be salt enough for pickling?
A. They put an egg into their brine. If the egg sinks the brine is not strong enough, if the egg floats it is.