the precipitate, ignite it intensely in a porcelain crucible, and weigh the pyrophosphate of magnesium which remains.

2 5

There was obtained 1.672 grammes of 2MgO, P2 O, (=0.6025 grammes MgO.). This result indicates 16.44 per cent. of magnesia in the epsom-salt. Theory requires 16.26 per cent.

The sulphuric acid could of course be determined by precipitating it with chloride of barium, as in Exp. II., or it may be estimated by the difference, as was done in the present case. The complete analysis was as follows:

Reduce a quantity of pure white marble to fine powder and dry it upon a water bath. place it in a beaker of 40 or 50 c. c. of water. and add dilute chlorhydric acid, little by little, to the water, until the whole of the marble has dissolved. About a hundred c. c. of the acid may be required to effect the solution. As soon as the marble has dissolved, fill the beaker half full of water and boil the mixture. Add a solution of oxalate of ammonium in slight excess, together with enough ammonia water to make the mixture alkaline. Leave the mixture at rest for twelve hours or more, then transfer the clear supernatant fluid to a six-inch filter, and wash the precipitate in the beaker, four or five times, by decantation. Finally, transfer the precipitate to the filter, and wash and dry in the usual way. Heat the precipitate in a porcelain crucible for fifteen minutes to a temperature just below redness, in order to convert the oxalate to carbonate of calcium. If the material analyzed were absolutely pure, and the work entirely accurate, the final weight of carbonate of calcium obtained, would of course be identical with the weight of marble taken.

Weigh out 3 or 4 grammes of the powder,

about 700 c. c. capacity, and pour upon it Cover the beaker with a glass plates

Since it is difficult to convert oxalate of calcium to the condition of carbonate, by ignition, without decomposing a portion of the latter, it is well to moisten the ignited precipitate (after it has been cooled and weighed) with a solution of carbonate of ammonium, to dry the mixture, first upon a water bath, and then over the lamp at a gentle heat, and again weigh it. This last weight will give the true amount of carbonate of calcium.

In our experiment 3.101 grammes of marble were taken, and 3.0975 grammes of carbonate of calcium were found. 3.0975 grammes of CaO, C O, represent 1.7346 grammes of CaO. Hence we found 55.93 per cent of lime, instead of the 56.00 per cent required by theory.

Numerous forms of apparatus for determining the proportion of carbonic acid in lime stone will be found figured in works relating to quantitative analysis.

[To be continued.]

SCHOOL EXPERIENCES.

SECOND.

IT has often occurred to me, Mr. Editor, when reading the strange changes recorded in the lives of men who have filled pages in universal history, that they are not, after all, exceptional characters. "The simple annals of the poor," though lacking the wide interest attached to the deeds of those who have founded or reformed communities, are, in miniature, quite as striking illustrations of variety in deeds or emotion as the former, if once our vision be contracted enough to examine their varying details. The lad who gains a name for honor or infamy in his village or town, is but a beginning of the subsequent development of the man, who by using the circumstances of life, becomes a Hampden or a Hastings. Change of residence or latitude, prosperity, adversity, embittered feelings engendered by trifles, pride sprung from flattery or temporary authority—these, and such as these, aid to make the broad sea that flows, deep and dark it may be, between

youth and maturity; between the high and the humble. And thus if great things may illustrate small ones, my change of residence, which, at the age of ten years, took me from my native country town to the neighborhood of a growing city, was an event which, as in a thousand other cases, has altered the whole course of an inconspicuous life.

My second home in childhood was upon the border of a somewhat remarkable New England river. Eastward lay on the left bank of the stream, and down its course, a swell of land of half a mile in ascent, bordered by the abrupt and wooded bank of the broad and noisy stream. Along the bank, and just within the stream at its usual height, were thousands of bowlders of every size and shape half submerged, but at times of high water completely covered, indicating their existence by large ripples and eddying whirlpools. Just above these, on the banks of a small creek which received a brook from a meadow stretching inland, was my home for many months. A new world here opened for me. In my entire life I had seen no body of water larger than the small winter pond, formed by some obstructed rivulet to turn a saw-mill for a few months: but here was a broad deep stream just above the rapids to whose locality I have alluded, and across this the road that passed our residence was continued by a ferry-boat of enormous dimensions, at least to my youthful eyes, being long enough to carry a stage-coach without unharnessing the team, and guided by a stout wire reaching from bank to bank.

But the small dories that were used to cross the stream were

even more attractive to me than the ferry-boat. I first saw one from the window of our parlor the evening we reached our hired house. The sun was nearly down, and as the oars rose and fell, his rays gave their broad blades the appearance of silver. How these aided in carrying my father and older brother toward the opposite shore, was as yet all a mystery; but none the less was my imagination excited. It may be doubted whether a bevy of flying men, crossing the air by some Dædalian contrivance, would more amaze a youth of ten at the present day, than a common Ames

bury dory at that time did my inexperience. How could they get back when the sun took the sheen from the water, on which they seemed to slide? How find the way in the darkness with no fences to mark their road? Should I ever see my brother and my father, thus swallowed up from view as they disappeared over the far shore? With such questions I plied my mother, wearied though she was with the long ride, and busied with household cares in a strange home. But little satisfaction was gained from her attempts to make me understand what so perplexed me. Yet this little was better than none, and a supper of fresh milk filled my stomach stopped my burning curiosity for the time, and, with my weariness sent me to sleep regardless of father, brother, river, dory, and all beside.

Inquisitive boys who go to sleep with unsatisfied curiosity are early risers. The morning sun shone brightly in at my window. My lost brother was lying by my side, asleep from the previous late evening's watch. I stole quietly from my place, dressed me hastily, and stealthily issued from the house to explore the mystery of the river. Following the sandy road a few rods by a circuitous direction, I came suddenly upon the ferry-boat leaving the shore with an early freight. But more wonderful than this, a neighbor was just landing in his dory, having it well laden with nice shad taken from a fly-net that he had anchored in the stream. His contented strokes as he brought the boat to land showed me the manner in whichmy fat her and brother had disappeared the evening before, and speedily dissipated the whole mystery of crossing the river with glittering oars. More than this. He cut a small stick with a fork in it, passed it through the mouth of the fish, and, calling me to him, said, "You are the Derby boy; I know you by your looks: you are just like your father. Here, take this as a present for his breakfast." I took, with some hesitation, the scaly creature, swung it over my shoulder as I had seen other burdens borne, and in a few minutes, to my parents' astonishment, stalked into the house with an air such as one exhibits who has done a good thing. Alas, for youthful exploits! They cooked the fish, and scolded the purveyor because he had gone to the river without leave, suggesting ominous terrors should he be guilty of a like offence.

If these dreaded promises damped my ardor for attempting

⚫ discoveries along the stream, they were more than balanced by the announcement on the part of my father that, in a few days, I was to attend a select school across the river, in the centre of the growing town, and to row over with him in the morning as he went to his occupation, and return at evening. Here were visions to stimulate a young peasant who had seen more domestic animals than men, and whose ideas of real life were less reliable than those which dribble from the diluted pages of some semi-monthly magazine of the present day. How I questioned, and mused, and fashioned what . I would do, and what become! How suddenly my best garments lost their attractiveness as I heard that the boys at Mr. Hewes's school wore real broadcloth caps and spencers and trousers; that some sported boots even. This was beyond anything Squire Rowell's son did in Royalton, though it were Sunday. And then what kind of a master was I to have, and how would the schoolhouse look, and where should I sit when I was there, and what books should I study? These interrogatories came up thick and somewhat disheartening, none the less so that no one could give me an intelligent answer. My brother had a place in a grocery as a boy to do everything which anybody wanted done, and had no time to make investigations or even to talk with me about my new fate. My father summed up what he knew, in the report that "Master Hewes knew what was best for boys and made them do it." My only remedy was patient waiting until time should solve my inquiries. There were sundry trips to and from the village shop on the part of my mother. Some of my few books were smoothed out and nicely covered with brown paper, on which "Daniel Derby's book" was written in good plain hand by a neighbor who had pretensions to scholarship. A cloth cap, to whose fashion I had hitherto been a stranger, was added to my best suit, and a new pair of real calf-skin shoes, a little too short for comfort, but the more fashionable, completed my personal presentment.

It was eight on a fine Monday morning, when my steps were directed to the little boat which was to bear me across the water my eyes had so often looked upon with longing. My new bravery