" 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 muc