Imagens da página
PDF
ePub

“ eager droppings into milk.” Finally, with ac-ies and the rest we may range edge, and the German Ecke, a corner, where I leave it.

In this way we can show how kindred ideas are expressed by related words, in the same language and in different languages. But if we would make etymology teach its profoundest lesson, and

steries

May seer hieroor), te 1001

one step more. We must show our pupils how the study of words, their origin, their use, and their changes of meaning, often disclose the subtle chains that unite the world of matter and the world of spirit. The idea that, “ everything visible has belonging to it an appropriate spiritual reality," has always been a favorite one of mysticism. And many of its devotees hare striven, by years of revery and attempted isolation of the spirit from all outward objects and impressions, to purge the mental vision to a clearer view of this secret correspondence. Swedenborg believed himself divinely commissioned to reveal the mysteries of this relation of the outer to the inner world. He looked upon the universe as a temple covered with hieroglyphics,” the writing of God's own hand. This may seem to our cold reason merely an idle fancy. But it is only the formal statement of the truth that makes us sceptical.

The poet believes it, and from thence derives all that delights us most in his song. It is the foundation of metaphor, and many of the words that are every day upon our lips, when questioned, will testify to its reality.

Flowers are, the world over, the emblems of the tender sentiments. How curiously we associate colors with virtues and vices ! White is the universal symbol of purity, as black is of moral guilt and baseness. Red typifies love ; and jealousy, we know from Shakspeare, is “green-eyed.” It does not surprise us that the merciless inquisitors of Spain sent their victims to the stake dressed in robes of yellow. And as little do we wonder that Correggio painted the drapery of the penitent Magdalene of blue, to denote the constancy of her love for the Saviour.

“Every word,” says Emerson," which is used to express a moral or intellectual fact, if traced to its root, is found to be borrowed from some material appearance. Right means straight; wrong means

twisted ; spirit primarily means wind ; transgression, the crossing of a line; supercilious, the raising of the eyebrow. We say the heart to express emotion, the head to denote thought; and thought and emotion are words borrowed from sensible things, and now appropriated to spiritual nature."

Who does not see that it is possible from such hints to open a new world of thought to young minds ? But you will say I have only pointed out the way by which the upper heights are to be ascended, meanwhile there is much hard climbing to be done below. I have done so because the first steps seem to me more evident. I do not think we can begin too soon with our pupils in helping them to observe, in the inflections of their grammar, and in their first reading lessons, the simplest cases of derivation. I should not be in haste to have rules committed to memory. It is, in my opinion, far better for the learner to arrive at the rule by noticing and comparing examples, than to reverse the process; and for the great majority, the exercise thus conducted has far greater interest. Doubtless the progress will seem much slower at first, but it will be more than compensated by the increased rapidity of subsequent acquisition, and especially by that habit of mind of which I have already spoken as the chief end, and which such a method seems best adapted to form. It is hardly necessary to suggest that the correspondence of English derivative endings with those of Latin and Greek should be constantly noticed. I should deem it of great importance to trace the etymology of words, so far as it is practicable, in the text that has passed before the pupil's eye. This can often be done very satisfactorily, especially in Homer; but the want of verbal indexes to the works usually read in preparatory schools, makes it somewhat difficult.

I cannot but think that it is in the power of teachers to add very greatly to the interest of classical study by following some such course as I have vaguely sketched. But here, as in all departments of education, more depends upon the spirit and ability of the teacher than upon the method. The teacher must lead the way. He must show the dignity and the value of this study, to make his pupils keenly observant and eager to gather knowledge. He must show how sometimes the etymology of a word, that ignorance may have corrupted, or use abraded, has put into the hand of the student of antiquity a clew by which he has traced out facts that otherwise must have forever remained hidden in impenetrable darkness, even as the Indian tracks his foe through a gloomy and pathless forest by here and there a crushed leaf or a broken twig.

EXAMPLES FOR PRACTICE IN QUANTITATIVE

CHEMICAL ANALYSIS. [By FRANK H. STORER, Professor in Massachusetts Institute of Technology.]

SEVERAL teachers, who have attended the free courses of instruction in General Chemistry and Qualitative Analysis, established at the Institute of Technology, through the liberality of the trustee of the Lowell Institute, have expressed a desire to prosecute the study of Quantitative Analysis also, - at least far enough to obtain a general idea of the methods actually employed in that branch of chemical art.

The object of the following communication is to show how read ily this desire may be gratified, even without access to a wellappointed laboratory.

In most manuals of Quantitative Analysis, and in most of the laboratories established for teaching students who are to pursue chemistry as a profession, the subject is treated of in such manner that a costly balance seems to be absolutely essential for the con. duct of accurate operations. The would-be amateur is usually disheartened at the first glance by this requirement, and led to re. gard the study as something not only occult in itself, but impracti cable for him, because expensive.

It must be remembered, however, that, though now indispensable to the professed chemist, the delicate “chemical balance” is, comparatively speaking, a thing of yesterday. The science has actually been built up, for the most part, through the use of far rougher implements, such as may now be obtained almost anywhere for a few dollars. There is in fact no real difficulty in making thoroughly satisfactory analyses of a great variety of substances, by means of a cheap balance, if the operator will but work with tolerably large quantities of his materials.

The advantage in using a delicate balance consists chiefly in the time gained by operating upon small quantities. Other things being equal, a precipitate, which weighs only a few grains, may evidently be collected, filtered and washed more readily than one weighing the same number of drachms.

The following analyses made under my direction, in the Institute's laboratory, by my assistant Mr. A. H. Pearson, may serve as examples of what can readily be accomplished by a careful manipulator tolerably familiar with chemical principles. It may be remarked that several of these analyses are better than the average of analyses made with fine balances and small quantities.

The apparatus required for the following experiments consists of a couple of sheets of “Swedish," and five or six sheets of ordinary filter paper; two glass stirring rods; two glass funnels, each large enough to carry a six-inch filter; three or four glass beakers; a couple of glass flasks, one of them fitted with tubes as a washbottle; a crucible and an evaporating dish of Berlin porcelain; a Bunsen's gas-burner, or an alcohol lamp; and an iron ring stand, furnished with a rough sheet-iron saucer,- for use as a sand bath ; a triangle of iron wire and a piece of wire-gauze four or five inches square. Instead of the ring stand, a tripod of stiff wire may be used. For esperiment No. VI. a burette will be needed also.

The balance actually used in the experiments here recorded was an apothecary's “prescription scale," capable of carrying 60 grammes or more on each pan, and delicate enough to move distinctly with a weight of two milligrammes. It was made by Becker & Sons, of 18 Exchange place, New York, and bought of their Boston agents, J. T. Brown & Co., corner of Washington and Bedford streets, for $8.60 in gold. The weights employed were a set of ordinary German gramme weights, worth five or six dollars.

With the exception of parts of Experiments VII. and VIII., all the operations described may be performed without trouble in any ordinary room. The evaporation of the acid liquor in Exp. VII. may be readily effected by placing the lamp, ring-stand and evaporating dish in a not too tight wooden box out of doors.

EXPERIMENT I. Determination of Iron by precipitation as sesquioxide.

Weigh out about 3 grammes of fine, tough iron-wire. Put the wire in a beaker of about a litre capacity, and pour upon it 30 or 40 c. c. of pure strong chlorhydric acid. Place the beaker on a sand bath or piece of wire gauze above the lamp, cover it with a piece of window glass, and heat its contents gently, so that the iron may dissolve with tolerable rapidity, but without violent ebullition. When the iron has dissolved, add 10 or 12 c. C. of strong nitric acid to the solution and continue to heat the mixture. Through the oxidizing power of nitric acid, the ferrous chloride will be changed to ferric chloride. Meanwhile, the liquid will become temporarily dark colored by dissolving a quantity of the hyponitric acid, which results from the reduction of the nitric acid. But after a few moments the liquor becomes clear again, as the nitrous funes escape, and then exhibits the character. istic reddish-brown color of ferric chloride. As soon as the temporary dark color has disappeared from the solution, lift the cover of the beaker and by means of a wash-bottle rinse back into the iron solution any particles of liquid which may have been thrown up during the action of the acid and left adhering to the plate. Dilute the iron solution with pure water enough to nearly fill the beaker, stir the mixture with a glass rod, and transfer half of it to another beaker of the same size as the first. Heat the contents of each beaker almost to boiling, stir the liquor and add to it, little by little, ammonia water, until the odor of the ammonia persists. A couple of filters of “Swedish paper," each of six inches diam. eter, will be sufficient to collect the whole of the hydrated sesquioxide of iron thus thrown down. To facilitate the process of filtering and washing, proceed as follows: Let the contents of each beaker stand at rest for a few moments in order that the hydrate of iron may settle; then pour into the filter the tolerably clear liquid which floats above the precipitate, and pour a quantity of boiling water upon the precipitate in the beaker. As soon as the misture of precipitate and water has settled again somewhat, pour

« AnteriorContinuar »