"You know there are many gold and silver mines in California," continued grandpa. "Near some of them large mines of quicksilver have been discovered. You can imagine that this caused great rejoicing, for all the quicksilver previously used was sent in ships to this part of the world, which, of course, made it scarce and very expensive. Now, we can send away quantities to other countries after supplying our own wants.
"Notwithstanding that this strange metal renders such service to mankind—for I could tell you of many other useful things it does—it is a deadly poison. Its vapor is so dangerous that persons searching for it often die from breathing the air where it is found. About seventy years ago, the mines in Austria, took fire, and thirteen hundred workmen were poisoned, and many of them died. The water that was used to quench the fire being pumped into the river Idria, all the fish died excepting the eels. Since that time, spiders and rats have deserted the mines.
"Mercury is carried in sheepskin bags and cast-iron bottles. It is so heavy that an ordinary cork would soon be forced out by it, therefore an iron stopper must be screwed in.
"Once, some bags of mercury were stored in the hold of a foreign vessel; unfortunately, a few of the bags were rotten and leaked. Every person on board was poisoned, and every piece of metal connected with the vessel received a silvery coating of mercury."
"It is dreadful! Fred, don't let us touch it," said Harry.
"Don't be frightened yet, Harry. Did you know that mercury is used as a medicine? It is given in very small doses."
"I am sure I shall never take it," exclaimed Fred.
"Perhaps you may have done so already," replied their grandfather, laughing. "Did you ever hear of blue-pill and calomel? They both are preparations of mercury."
Just then the sun shone into the room so brightly that every one turned to the windows. Such a sparkle! The evergreens were covered with shining ice-drops, and the tall trees pointed their glistening branches toward the few clouds that were hurrying over the blue sky.
"I am not sorry it rained, after all," said Fred. "I have enjoyed the morning so much that I forgot the play we were going to have."