Result: Shell dissolved. (3). Solution muriate of lime. " Carbonate of potassium. Result: Solid. From these simple but important discoveries they proceeded to move difficult analyses and syntheses. They made ammonia water; they combined weights; they experimented in acids, bases and salts; they produced explosions; they almost set the house on fire with their experiments in hydrogen; they tested iodine and chlorine. The greatest hindrance to their advancement was the amount of care required. They had burnt holes in their clothes; the laundry had became an inconvenient refuge for the cats and dogs of the house; the younger children could no longer play there, but broken glass should injure them; and the maids dreaded entering a place where unlooked-for events were always happening. A crisis was at last developed by the gift of a friend who sent them some lumps of "Sulphuret Potass" which the boys heated, when a strange and still stranger odor arose. Absorbed in their experiments, they heard neither approaching footsteps nor voices; the door was even opened, but quickly shut. At last Ned's mother courageously rushed up to them holding her handkerchief tight over her face, and insisted with unmistakable gestures upon their leaving the laundry. The odor had penetrated every nook and corner of the house, a committee meeting had vanished, and windows were all thrown open. "This is an end to your chemistry," she declared in injured tones; "you have discovered nothing except how to make yourselves sick, have injured your coats and trousers, and I won't have any more of it, do you understand?" "Yes," said both boys meekly. Perhaps they were rather glad than otherwise of any expression of authority which could plausibly end what they were secretly longing to give up. As partners they had been faithful to each other's interests; but did it pay to give up base-ball, week after week, just to carry out an idea! Hal's money was gone, and both boys had done a large amount of "trading" of books and curiosities for some other boys' half-used chemical stock. Ned was sure he knew enough to aid him in his profession; and Hal valued failure as an exponent in indicating, negatively, his future career. "Glad of it;" Ned ventured to assert at last when the family had dispersed and windows were closed. "We must clean up, and we might as well sell out the whole concern, take account of stock, and divide the profits." "Don't flatter yourself," replied Hal, "that there'll be much profit. If there is I ought to have two thirds of it as I put in the most capital." "Yes, as far as cash goes, but brains count too, and I think you will admit that the ideas have been furnished by me chiefly; besides my trousers were burned more than yours. But I don't care--divide things as you like. I am agreed." II. AS OFFICE BOY.