« AnteriorContinuar »
The water comes out with considerable force from the five-inch opening, and a heavy body thrown into the mouth of the well is rejected almost as readily as a piece of pine wood. By an approximate calculation, its mechanical force is equal to that of a steam engine with cylinder 10 by 18 inches, under 50 lbs. pressure, with a speed of 55 revolutions per minnte, a force rated at about 10 horse power. The top of the well is now closed, and the water conducted about 30 feet to a basin with a large jet d'eau on the centre, from which there is a central jet of water 40 feet in height, with a large water pipe, from which the water passes in the form of a sheaf. When the whole force of water is allowed to expend itself on the central jet, it is projected to the height of from 90 to 100 feet, settling down to a steady flow of a stream 60 feet high.
Temperature of the Water. The water, as it flows from the top of the well has a constant temperature of 767° F., and is not affected either by the heat of summer or the cold of winter. The temperature at the bottom of the well is several degrees higher than this, as ascertained by sinking a Walferdin's registering thermometer to the bottom, which indicated 821° F. Taking as correct data that the point of constant temperature below the surface of Louisville is the same as at Paris, namely, 53° F., at 90 feet below the surface, we have an increase of 1° of temperature for every 67 feet below that point. The increase in Paris is 1° for every 61th feet. The temperature of the water is sufficient for comfortable bathing during most of the year, a circumstance that will be of considerable importance, if it ever be turned to the use of baths. The reason of the difference of 6° between the water at the bottom of the well and at the top is, that the iron pipe leading from the surface to the rock passes through a stratum of water 60 feet thick, having a temperature of 570.
The Source of the Water.—The question naturally arises, if the vein of water supplying this well has a connection with some distant source higher than the surface of Louisville, where is that source? From all that we have been able to learn of the geology of this county, taking Louisville as a center, the first rocks encountered corresponding to the sandstone (in which the water of the artesian well was struck) are in Mercer, Jessamine, and Garrard counties, near Dix Creek, to the east of Harrodsburg. The rocks there are said to be cavernous and water-bearing. The elevation is about 500 feet greater than Louisville, and about 75 miles in a straight line from this city.
This being the most probable source of the water, from whence come its mineral constituents? These are obtained from the rocks through which it percolates in its way from its source to the point below Louisville, where it has been tapped, and where
it will doubtless flow in undiminished quantity for centuries to come, as wells having such deep sources as this, are usually inexhaustible.
Nature of the Water.— The water is perfectly limpid, with a temperature as already stated of 764°, which will be invariable all the year round.
Its specific gravity is 1.0113. The solid contents left on evaporating one wine gallon to dryness are 9153 grains, furnishing on analysis:
. . 14.7757 " Potassium,
4.2216 6 Aluminum, .
1.2119 4 Lithium,
0.1012 Sulphate of Soda,
72.2957 * Lime,
29.4342 « Magnesia,
1.8012 “ Potash,
3:2248 Bicarbonate of Soda, .
5.9915 Magnesia, ..
2.7558 66 Iron,
0:3518 Phosphate of Soda,
1:5415 Iodid of Magnesium,
0:3547 Bromid of Magnesium, .
0.8857 Organic Matter, .
0.7082 Loss in analysis, - .
Nitrogen, - - - - - 1.3580 The analysis was performed by the usual methods; but as chlorid of lithium was sought for and found, it may be of interest to detail the method of research in this particular, as a guide to similar investigations of other mineral waters in this country. Ten gallons of water were evaporated to about two pints, (there was an abundant deposition of salts,) to this was added one gallon of 95 per ct. alcohol; it was then thrown on a filter, and the salts on the filter washed with alcohol of the same strength-the filtered liquid was evaporated nearly to dryness; in the present instance the residue consisted of a few ounces of a thick syrupy liquid; to this was added one pint of absolute alcohol, addi. tional salts were precipitated; the liquid was again filtered and evaporated nearly to dryness—to it were added 8 oz. distilled water and two ounces of milk of lime, (pure lime made by igniting carbonate of lime prepared by carbonate of ammonia,) the lime was added for the purpose of precipitating the magnesia and alumina—again filtered and washed; the filtered liquid was somewhat concentrated, and while warm, carbonate of ammonia added to precipitate the lime; it was then filtered and evaporated to about a fluid ounce and treated with a little lime water and carbonate of ammonia alternately, to insure the absence of the last traces of magnesia and lime.
Before going further, it would be well to state that the treatment of alcohol separates the great mass of salts that are held in solution by the water, and which interfere with the detection of so minute a constituent as the lithium salt-by the alcohol we reduce the salts to small amounts of chlorids of magnesium, aluminum, calcium, sodium, potassium and lithium; by the lime the first two are got rid of, and by the carbonate of ammonia the lime is precipitated.
The solution, now containing the chlorids of sodium, potassium, lithium and ammonium, is evaporated to dryness, and the residue heated to dull redness, by which the ammonia salt is expelled and a little organic matter destroyed; the residue is next dissolved in water, and a drop or two of the liquid tested for a sulphate; should this be present it must be got rid of by exact neutralization with chlorid of barium, (a slight excess of the chlorid of barium will not interfere with the other steps in the analysis); in the examination of the water in question no trace of sulphate was found at this stage of the process, so it was again evaporated to dryness in a small capsule over a water bath; there were now a few grains of residual matter. To this was added an ounce of a mixture of equal parts of pure ether and absolute alcohol, the capsule was covered with a small receiver and allowed to stand for 18 hours; the liquid was then thrown on a small filter, and the filter washed with a little of the mix. ture of ether and alcohol. The alcoholic ether solution evaporated to dryness furnished the chlorid of lithium recognized by its well known characteristics. Although this process requires considerable time and some careful manipulation, its results are both accurate and satisfactory.
The water of this artesian well has very valuable medical properties, and those readers who are curious to examine into these points, will obtain all the required information by sending to Louisville for the medical report.
ART. XXI.—On Modes of increasing the Heat of the Mouth Blow
pipe, and some new Blowpipe Manipulations, by Prof. HENRY WURTZ, of the National Medical College, Washington, D. C.
[Read, with experimental illustrations, before the American Association for the
Advancement of Science, at Baltimore, April, 1858.)
In the course of some blowpipe investigations which I have in progress, it has been found extremely difficult, and sometimes impossible, to obtain in the ordinary way sufficient heat for the production of certain desired effects. Attempts were therefore made to devise means of increasing the heating power of the instrument, and this object has been so far attained, and by means so simple and efficient, that I take this opportunity to make these means public, that others may also be benefitted thereby. To blowpipe analysts it is not necessary for me to detail the advantages to be gained in many cases by a practicable mode of increasing the heat, of which advantages not the least important is the saving of time. ·
It was first observed that in the ordinary mode of manipulation, a great part of the heat was conducted away from the bead by the cold part of the platinum wire contiguous to it. This is easily prevented by simply bending the wire previously, at right angles about an inch or an inch and a half from the loop that is to hold the bead.* On then holding the bead at the point of the blue cone of the flame, and the wire so that the bent portion is coincident with a continuation of the axial line of the flame, this bent portion becomes also heated to high redness, losing thus in a great degree its tendency to abstract heat from the bead. By this little contrivance alone the heat is increased to so important a degree, that I venture to think that no one who has once tried it, will ever use a wire of any other form.
I next directed my attention to the combustible used. An ordinary alcohol flame, as every one knows, gives with the blowpipe a comparatively feeble heat. A gas flame is much superior, and a large wax candle gives probably a higher heat than any thing else at present commonly in use among blowpipe operators. It occurred to me that the heating effect was probably propor. tional to the density of the burning vapor, or the quantity of combustible matter contained in the same volume. I therefore searched for combustibles having a high density of vapor, and found that the paraffine of Reichenbach, now known from the investigations of Hofstaedter* and Filipuzzit to be a mixture of different isomeric hydrocarbons, all of which must have very high equivalents, was found by Lewył to have a vapor-density of not less than 11.8. By inquiry, I found that candles composed of this, or a similar material, obtained from the products of distillation of the well-known “Breckenridge Coal,” could be bought in New York. On procuring some of these, and using them as pabulum for the blowpipe-jet, I found my anticipations fully realized. The flame obtained by means of the paraffine candle is much hotter than that from a wax candle. Unfortunately the candles made in New York are small, and have extremely small wicks, which renders them difficult to manipulate with, because the least motion of the jet-piece, by throwing it out of the centre of the flame, deranges the form of the cone. This can of course be easily remedied by having larger candles made with larger wicks.
* At the time the above was read, I had no suspicion that the contrivance of bending the wire had ever been published before, or thought of, by any other than myself. Since, however, Prof. Brush of New Haven has directed my attention to a passage in the last edition (1853) of Plattner's “ Probirkupst mit dem Löthrobre,” page 14, wbere the same device is identically described, as used for fusing platinum wire. I desire, therefore, stating at the same time that I have been in the habit of using it for more than ten years, to disavow all claim to priority, hoping still that some novelty may be found in my modes of making use of the invention.-H. W.
Next, and lastly, the blowpipe itself seemed to me susceptible of improvement, by the introduction of an agent to absorb the moisture and carbonic acid of the breath, which must necessarily diminish the heating power of the flame. I have therefore sought to eliminate these obstacles by using, instead of the tube of the ordinary blowpipe, a somewhat larger tube filled with fragments of caustic potash. In the instrument which I have heretofore used, and which I now exhibit, this tube is composed of glass, and is united with the jet-piece of an ordinary blow. pipe of Berzelius' form by means of a perforated cork; but of course in practice this tube may as well be composed of metal to avoid breakage. I use the ordinary potassa fusa, occurring in the shops in the form of sticks, broken up to about the size of a split pea, the fragments being confined in the tube by a plug of cotton at each end. It is advisable, when this kind of blowpipe is not in use, to keep the upper end of the tube corked. It remains yet to be seen whether the additional advantage gained by using a blow pipe of this construction will compensate for the concomitant inconveniences, though the latter are far less important, according to my own experience, than many would suppose.
Now as to the effects which may be produced by the combination of these several appliances. Platinum wire of medium blowpipe size is fused with little difficulty, and I have obtained beads of considerable diameter. Fine platinum wire melts down
* Liebig and Kopp's Jahresbericht, 1854, 608.