Chapter IV: Part 4

The writer on other occasions applied single tests (the collodion test) to samples of beechwood creosote that he had an opportunity of procuring small specimens of, and satisfied himself that they were pure. The conclusion is that the wood creosote of the market of the present time is in abundant supply, is of unexceptionable quality, and reasonable in price, so that there is no excuse for the substitution of the phenol commonly sold for it. When it is directed for use for internal administration (the medicinal effect being entirely dissimilar), wood creosote only should be dispensed.

The general sales of creosote by the pharmacist are in small quantities as a toothache remedy, and phenol has the power of coagulating albumen, which effectually relieves the suffering. Wood creosote does not coagulate albumen, and is, therefore, not as serviceable. This is, perhaps, the reason that it has become, in a great measure, supplanted in general sale by the coal tar creosote, to say nothing of the argument of a lower cost.

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REMEDY FOR SICK HEADACHE.

Surgeon Major Roehring, of Amberg, reports, in No. 32 of the _Allg. Med. Centr. Zeit_., April 22, 1882, a case of headache of long standing, which he cured by salicylate of sodium, which confirms the observations of Dr. Oehlschlager, of Dantzig, who first contended that we possessed in salicylic acid one of the most reliable remedies for neuralgia. This cannot astonish us if we remember that the action of salicylic acid is, in more than one respect, and especially in its influence on the nervous centers, analogous to quinine.

While out with the troops on maneuver, Dr. Roehring was called to visit the sixteen-year old son of a poor peasant family in a neighboring village. The boy, who gave all evidences of living under bad hygienic surroundings, but who had shown himself very diligent at school, had been suffering, from his sixth year, several days every week from the most intense headache, which had not been relieved by any of the many remedies tried for this purpose. A careful examination did not reveal any organic lesion or any cause for the pain, which seemed to be neuralgic in character, a purely nervous headache. Roehring had just been reading the observations of Oehlschlager, and knowing, from the names of the physicians who had been already attending the poor boy, that all the common remedies for neuralgia had been given a fair trial, thought this a good opportunity to test the virtue of salicylate of sodium. He gave the boy, who, in consequence of the severity of the pain, was not able to leave his bed, ten grains of the remedy every three hours, and was surprised to see the patient next day in his tent and with smiling face. The boy admitted that he for years had not been feeling so well as he did then. The remedy was continued, but in less frequent doses, for a few days longer; the headache did not return. Several months later Dr. Roehring wrote to the school-teacher of the boy, and was informed that the latter had, during all this time, been totally free of his former pain, that he was much brighter than formerly, and evidently enjoying the best of health.

It may be worth while to give the remedy a more extensive trial, and the more so as we are only too often at a loss what to do in stubborn cases of so-called nervous headache.--_The Medical and Surgical Reporter_.

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SUNLIGHT AND SKYLIGHT AT HIGH ALTITUDES.

At the Southampton meeting of the British Association, Captain Abney read a paper in which he called attention to the fact that photographs taken at high altitudes show skies that are nearly black by comparison with bright objects projected against them, and he went on to show that the higher above the sea level the observer went, the darker the sky really is and the fainter the spectrum. In fact, the latter shows but little more than a band in the violet and ultraviolet at a height of 8,500 feet, while at sea-level it shows nearly the whole photographic spectrum. The only reason of this must be particles of some reflecting matter from which sunlight is reflected. The author refers this to watery stuff, of which nine-tenths is left behind at the altitude at which be worked. He then showed that the brightness of the ultra-violet of direct sunlight increased enormously the higher the observer went, but only to a certain point, for the spectrum suddenly terminated about 2,940 wave-length. This abrupt absorption was due to extra-atmospheric causes and perhaps to space. The increase in brightness of the ultra-violet was such that the usually invisible rays, L, M, N, could be distinctly seen, showing that the visibility of these rays depended on the intensity of the radiation. The red and ultra-red part of the spectrum was also considered. He showed that the absorption lines were present in undiminished force and number at this high altitude, thus placing their origin to extra-atmospheric causes. The absorption from atmospheric causes of radiant enemy in these parts he showed was due to "water-stuff," which he hesitated to call aqueous vapor, since the banded spectrum of water was present, and not lines. The B and A line he also stated could not be claimed as telluric lines, much less as due to aqueous vapor, but must originate between the sun and our atmosphere. The author finally confirmed the presence of benzine and ethyl in the same region. He had found their presence indicated in the spectrum at sea-level, and found their absorption lines with undiminished intensity at 8,500 feet. Thus, without much doubt, hydrocarbons must exist between our atmosphere and the sun, and, it may be, in space.

Prof. Langley, following Capt. Abney, observed: The very remarkable paper just read by Captain Abney has already brought information upon some points which the one I am about, by the courtesy of the Association, to present, leaves in doubt. It will be understood then that the references here are to his published memoirs only, and not to what we have just heard.

The solar spectrum is so commonly composed to have been mapped with completeness, that the statement that much more than one-half its extent is not only unmapped but nearly unknown, may excite surprise. This statement is, however, I think, quite within the truth, as to that almost unexplored region discovered by the elder Herschel, which, lying below the red and invisible to the eye, is so compressed by the prism that, though its aggregate heat effects have been studied through the thermopile, it is only by the recent researches of Capt. Abney that we have any certain knowledge of the lines of absorption there, even in part. Though the last-named investigator has extended our knowledge of it to a point much beyond the lowest visible ray, there yet remains a still remoter region, more extensive than the whole visible spectrum, the study of which has been entered on at Alleghany, by means of the linear bolometer.

The whole spectrum, visible and invisible, is powerfully affected by the selective absorption of our atmosphere and that of the sun; and we must first observe that could we get outside our earth's atmospheric shell, we should see a second and very different spectrum, and could we afterward remove the solar atmosphere also, we should have yet a third, different from either. The charts exhibited show:

1st. The distribution of the solar energy as we receive it, at the earth's surface, throughout the entire invisible as well as visible portion, both on the prismatic and normal scales. This is what I have principally to speak of now, but this whole first research is but incidental to others upon the spectra before any absorption, which though incomplete, I wish to briefly allude to later. The other curves then indicate:

2d. The distribution of energy before absorption by our own atmosphere.

3d. This distribution at the photosphere of the sun. The extent of the field, newly studied, is shown by this drawing [chart exhibited]. Between H in the extreme violet, and A in the furthest red, lies the visible spectrum, with which we are familiar, its length being about 4,000 of Angstrom's units. If, then, 4,000 represent the length of the visible spectrum, the chart shows that the region below extends through 24,000 more, and so much of this as lies below wave-length 12,000, I think, is now mapped for the first time.

We have to pi = 12,000 relatively complete photographs, published by Capt. Abney, but, except some very slight indications by Lamansky, Desains, and Mouton, no further guide.

Deviations being proportionate to abscissae, and measured solar energies to ordinates, we have here (1) the distribution of energy in the prismatic, and (2) its distribution in the normal spectrum. The total energy is in each case proportionate to the area of the curve (the two very dissimilar curves inclosing the same area), and on each, if the total energy be roughly divided into four parts, one of these will correspond to the visible, and three to the invisible or ultra-red part. The total energy at the ultra violet end is so small, then, as to be here altogether negligible.

We observe that (owing to the distortion introduced by the prism) the maximum ordinate representing the heat in the prismatic spectrum is, as observed by Tyndall, below the red, while upon the normal scale this maximum ordinate is found in the orange.

I would next ask your attention to the fact that in either spectrum, below pi = 12,000 are most extraordinary depressions and interruptions of the energy, to which, as will be seen, the visible spectrum offers no parallel. As to the agent producing these great gaps, which so strikingly interrupt the continuity of the curve, and, as you see, in one place, cut it completely into two, I have as yet obtained no conclusive evidence. Knowing the great absorption of water vapor in this lowest region, as we already do, from the observations of Tyndall, it would, _a priori_, seem not unreasonable to look to it as the cause. On the other hand, when I have continued observations from noon to sunset, making successive measures of each ordinate, as the sinking sun sent its rays through greater depths of absorbing atmosphere, I have not found these gaps increasing as much as they apparently should, if due to a terrestrial cause, and so far as this evidence goes, they might be rather thought to be solar. But my own means of investigation are not so well adapted to decide this important point as those of photography, to which we may yet be indebted for our final conclusion.

I am led, from a study of Capt. Abney's photographs of the region between pi = 8,000 and pi = 12,000, to think that these gaps are produced by the aggregation of finer lines, which can best be discriminated by the camera, an instrument which, where it can be used at all, is far more sensitive than the bolometer; while the latter, I think, has on the other hand some advantage in affording direct and trustworthy measures of the amount of energy inhering in each ray.

One reason why the extent of this great region has been so singularly underestimated, is the deceptively small space into which it appears to be compressed by the distortion of the prism. To discriminate between these crowded rays, I have been driven to the invention of a special instrument. The bolometer, which I have here, is an instrument depending upon principles which I need not explain at length, since all present may be presumed to be familiar with the success which has before attended their application in another field in the hands of the President of this Association.

I may remark, however, that this special construction has involved very considerable difficulties and long labor. For the instrument here shown, platinum has been rolled by Messrs. Tiffany, of New York, into sheets, which, as determined by the kindness of Professor Rood, reach the surprising tenuity of less than one twenty-five-thousandth of an English inch (I have also iron rolled to one fifteen-thousandth inch), and from this platinum a strip is cut one one-hundred-and-twenty-fifth of an inch wide. This minute strip, forming one arm of a Wheatstone's bridge, and thus perfectly shielded from air currents, is accurately centered by means of a compound microscope in this truly turned cylinder, and the cylinder itself is exactly directed by the arms of this Y.

The attached galvanometer responds readily to changes of temperature, of much less than one-ten-thousandth degree F. Since it is one and the same solar energy whose manifestations we call "light" or "heat," according to the medium which interprets them, what is "light" to the eye is "heat" to the bolometer, and what is seen as a dark line by the eye is felt as a cold line by the sentient instrument. Accordingly, if lines analogous to the dark "Fraunhofer lines" exist in this invisible region, they will appear (if I may so speak) to the bolometer as cold bands, and this hair-like strip of platina is moved along in the invisible part of the spectrum till the galvanometer indicates the all but infinitesimal change of temperature caused by its contact with such a "cold band." The whole work, it will be seen, is necessarily very slow; it is in fact a long groping in the dark, and it demands extreme patience. A portion of its results are now before you.

The most tedious part of the whole process has been the determination of the wave-lengths. It will be remembered that we have (except through the work of Capt. Abney already cited, and perhaps of M. Mouton) no direct knowledge of the wave-lengths in the infra-red prismatic spectrum, but have hitherto inferred them from formulas like the well-known one of Cauchy's, all which known to me appear to be here found erroneous by the test of direct experiment, at least in the case of the prism actually employed.

I have been greatly aided in this part of the work by the remarkable concave gratings lately constructed by Prof. Rowland, of Baltimore, one of which I have the pleasure of showing you. [Instrument exhibited.]

The spectra formed by this fall upon a screen in which is a fine slit, only permitting nearly homogeneous rays to pass, and these, which may contain the rays of as many as four overlapping spectra, are next passed through a rock-salt or glass prism placed with its refracting edge parallel to the grating lines. This sorts out the different narrow spectral images, without danger of overlapping, and after their passage through the prism we find them again, and fix their position by means of the bolometer, which for this purpose is attached to a special kind of spectrometer, where its platinum thread replaces the reticule of the ordinary telescope. This is very difficult work, especially in the lowermost spectrum, where I have spent over two weeks of consecutive labor in fixing a single wave-length.

The final result is, I think, worth, the trouble, however, for, as you see here, we are now able to fix with approximate precision and by direct experiment, the wave-length of every prismatic spectral ray. The terminal ray of the solar spectrum, whose presence has been certainly felt by the bolometer, has a wave-length of about 28,000 (or is nearly two octaves below the "great A" of Fraunhofer).

So far, it appears only that we have been measuring _heat_, but I have called the curve that of solar "energy," because by a series of independent investigations, not here given, the selective absorption of the silver, the speculum-metal, the glass, and the lamp-black (the latter used on the bolometer-strip), forming the agents of investigation, has been separately allowed for. My study of lamp-black absorption, I should add in qualification, is not quite complete. I have found it quite transparent to certain infra-red rays, and it is very possible that there may be some faint radiations yet to be discovered even below those here indicated.

In view of the increased attention that is doubtless soon to be given to this most interesting but strangely neglected region, and which by photography and other methods is certain to be fully mapped hereafter, I can but consider this present work less as a survey than as a sketch of this great new field, and it is as such only that I here present it.

All that has preceded is subordinate to the main research, on which I have occupied the past two years at Alleghany, in comparing the spectra of the sun at high and low altitudes, but which I must here touch upon briefly. By the generosity of a friend of the Alleghany Observatory, and by the aid of Gen. Hazen, Chief Signal Officer of the U S. Army, I was enabled last year to organize an expedition to Mount Whitney in South California, where the most important of these latter observations were repeated at an altitude of 13,000 feet. Upon my return I made a special investigation upon the selective absorption of the sun's atmosphere, with results which I can now only allude to.

By such observations, but by methods too elaborate for present description, we can pass from the curve of energy actually observed to that which would be seen if the observer were stationed wholly above the earth's atmosphere, and freed from the effect of its absorption.

The salient and remarkable result is the growth of the blue end of the spectrum, and I would remark that, while it has been long known from the researches of Lockyer, Crova, and others that certain rays of short wave-length were more absorbed than those of long, these charts show _how much_ separate each ray of the spectrum has grown, and bring, what seems to me, conclusive evidence of the shifting of the point of maximum energy without the atmosphere toward the blue. Contrary to the accepted belief, it appears here also that the absorption on the whole grows less and less, to the extreme infra-red extremity; and on the other hand, that the energy before absorption was so enormously greater in the blue and violet, that the sun must have a decidedly bluish tint to the naked eye, if we could rise above the earth's atmosphere to view it.

But even were we placed outside the earth's atmosphere, that surrounding the sun itself would still remain, and exert absorption. By special methods, not here detailed, we have at Alleghany compared the absorption, at various depths, of the sun's own atmosphere for each spectral ray, and are hence enabled to show, with approximate truth, I think for the first time, the original distribution of energy throughout the visible and invisible spectrum at the fount of that energy, in the sun itself. There is a surprising similarity, you will notice, in the character of the solar and telluric absorptions, and one which we could hardly have anticipated _a priori_.

Here, too, violet has been absorbed enormously more than the green, and the green than the red, and so on, the difference being so great, that if we were to calculate the thickness of the solar atmosphere on the hypothesis of a uniform transmission, we should obtain a very thick atmosphere from the rate of absorption in the infra-red alone, and a very thin one from that in the violet alone.

But the main result seems to be still this, that as we have seen in the earth's atmosphere, so we see in the sun's, an enormous and progressive increase of the energy toward the shorter wave-lengths. This conclusion, which, I may be permitted to remark, I anticipated in a communication published in the _Comptes Rendus_ of the Institute of France as long since as 1875, is now fully confirmed, and I may mention that it is so also by direct photometric methods, not here given.

If, then, we ask how the solar photosphere would appear to the eye, could we see it without absorption, these figures appear to show conclusively that it would be _blue_. Not to rely on any assumption, however, we have, by various methods at Allegheny, reproduced this color.

Thus (to indicate roughly the principle used), taking three Maxwell's disks, a red, green, and blue, so as to reproduce white, we note the three corresponding ordinates at the earth's surface spectrum, and, comparing these with the same ordinates in the curve giving the energy at the solar surface, we rearrange the disks, so as to give the proportion of red, green, and blue which would be seen _there_, and obtain by their revolution a tint which must approximately represent that at the photosphere, and which is most similar to that of a blue near Fraunhofer's "F."

The conclusion, then, is that, while all radiations emanate from the solar surface, including red and infra-red, in greater degree than we receive them, the blue end is so enormously greater in proportion that the proper color of the sun, as seen at the photosphere is blue--not only "bluish," but positively and distinctly blue; a statement which I have not ventured to make from any conjecture, or on any less cause than on the sole ground of long continued experiments, which, commenced some seven years since, have within the past two years irresistibly tended to the present conclusion.

The mass of observations on which it rests must be reserved for more detailed publication elsewhere. At present, I can only thank the association for the courtesy which has given me the much prized opportunity of laying before them this indication of methods and results.

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THE MINERALOGICAL LOCALITIES IN AND AROUND NEW YORK CITY, AND THE MINERALS OCCURRING THEREIN.

[Footnote: Continued from SUPPLEMENTS 244 and 246.]

By NELSON H. DABTON.

PART III.

Hoboken.--The locality represented here is where the same serpentine that we met on Staten Island crops out, and is known as Castle Hill. It is a prominent object in view when on the Hudson River, lying on Castle Point just above the Stevens Institute and about a mile north of the ferry from Barclay or Christopher Street, New York city. Upon it is the Stevens estate, etc., which is ordinarily inaccessible, but below this and along the river walk, commencing at Fifth Street and to Twelfth, there is an almost uninterrupted outcrop from two to thirty feet in thickness and plentifully interspersed with the veins of the minerals of the locality, which are very similar to those of Staten Island; the serpentine, however, presenting quite a different appearance, being of a denser and more homogeneous structure and color, and not so brittle or light colored as that of Staten Island, but of a pure green color. The veins of minerals are about a half an inch to--in the case of druses of magnesite, which penetrate the rock in all proportions and directions--even six inches in thickness. They lie generally in a perpendicular position, but are frequently bent and contorted in every direction. They are the more abundant where the rock is soft, as veins, but included minerals are more plentiful in the harder rock. There is hardly any one point on the outcrop that may be said to be favored in abundance, but the veins of the brucites, dolomite, and magnesites are scattered at regular and short intervals, except perhaps the last, which is most plentiful at the north end of the walk.

_Magnesite_.--This mineral, of which we obtained some fine specimens on Staten Island, occurs extremely plentifully here, constituting five or six per cent. of a large proportion of the rock, and in every imaginable condition, from a smooth, even, dark colored mass apparently devoid of crystalline form, to druses of very small but beautiful crystals, which are obtained by selecting a vein with an opening say from a quarter to a half-inch between it and one or, if possible, both points of its contact with the inclosing rock, and cutting away the massive magnesite and rock around it, when fine druses and masses or geodes may be generally found and carefully cut out. The crystals are generally less than a quarter of an inch long, and the selection of a cabinet specimen should be based more upon their form of aggregation that the size of the crystals. Nearly all the veins hold more or less of these masses through their total extent, but many have been removed, and consequently a careful search over the veins for the above indications, of which there are still plenty undeveloped or but partly so, would well repay an hour or more of cutting into, by the specimens obtained. Patience is an excellent and very necessary virtue in searching for pockets of minerals, and is even more necessary here among the multitudinous barren veins. One hint I might add, which is of final importance, and the ignorance of which has so far preserved this old locality from exhaustion, is that every specimen of this kind in the serpentine, of any great uniqueness, is to be found within five feet from the upper or surface end of the vein, which in this locality is inaccessible in the more favored parts without a ladder or similar arrangement upon which one may work to reach them. Here the veins will be found to be very far disintegrated and cavernous, thus possessing the requisite conditions of occurrence (this is also true of Staten Island, but there more or less inaccessible) for this mineral and similar ones that occur in geodes or drused incrustations, while it is just _vice versa_ for those occurring in closely packed veins, as brucite, soapstone, asbestos, etc., where they occur in finer specimens, where they are the more compact, which is deep underground. This is also partly true of the zeolites and granular limestone species with included minerals. I do not think there is any rule, at least I have not observed it in an extended mineralogical experience; but if they favor any part, it is undoubtedly the top, as in the granular limestone and granite; however, they generally fall subordinate to the first principle, as they more frequently, in this formation, with the exception of chromic iron, occur not in the serpentine but in the veins therein contained; for instance, crystals of dolomite are found deeper in the rock as they occur in the denser soapstone, which becomes so at a more or less considerable depth, with spinel, zircon, etc., of the granular limestone. They occur generally in pockets within five feat from the surface, but they can hardly be called included minerals, as they are rather, as their mention suggests, pockets, and adjacent or in contact with the intruded granite or metamorphosed rock joining the formation at this point. This is seemingly at variance when we consider datholite, but when we do find it in pockets a hundred and fifty feet below the surface, in the Weehawken tunnel, it is not in the trap, but on the surface of what was a cleft or empty vein, since filled up with chlorite extending from the surface down, while natrolite, etc., by the trap having clefts of such variable and often great depth, allowed the solution of the portion thus contributed that infiltered from the surface easy access to the beds in which they lie, the mode of access being since filled with densely packed calcite, which was present in over-abundance. This is not applicable to serpentine, as the clefts are never of any great depth, and the five feet before mentioned are a proportionately great depth from the surface. As I mentioned in commencing this paper (Part I), every part of the success of a trip lies in knowing where to find the minerals sought; and by close observation of these relations much more direction may be obtained than by my trying to describe the exact point in a locality where I have obtained them or seen them. There is much more satisfaction in finding rich pockets independently of direction, and by close observance of indications rather than chance, or by having them pointed out; for the one that reads this, and goes ahead of you to the spot, and either destroys the remainder by promiscuous cuttings, or carries them off in bulk, as there are many who go to a locality, and what they cannot carry off they destroy, give you a disappointment in finding nothing; consequently, I have considered that this digression from our subject in detail was pardonable, that one may be independent of the stated parts of the locality, and not too confidently rely on them, as I am sometimes disappointed myself in localities and pockets that I discover in spare time by finding that some one has been there between times, and carried off the remainder. The characteristics of magnesite I have detailed under that head under Pavilion Hill, Staten Island; but it may be well to repeat them briefly here. Form as above described, from a white to darker dirty color. Specific gravity, 2.8-3; hardness, about 3.5. Before the blowpipe it is infusible, _and not reduced to quicklime_, which distinguishes it from dolomite, which it frequently resembles in the latter's massive form, common here in veins. It dissolves in acid readily with but little effervescence, which little, however, distinguishes it from brucite, which it sometimes resembles and which has a much lower-specific gravity when pure.

_Dolomite_.--This mineral has been very common in this locality. It differs, perhaps, as I have before explained, from magnesite in containing lime besides magnesia, and from calc spar by the _vice versa_. Much of the magnesite in this serpentine contains more or less lime, and is consequently in places almost pure dolomite, although crystals are seldom to be found in this outcrop, it all occurring as veins about a half-inch thick and resembling somewhat the gurhofite of Staten Island, only that it is softer and less homogeneous in appearance. Its color is slightly tinged green, and specimens of it are not peculiarly unique, but perhaps worth removing. Its characteristics are: first, its burning to quicklime before the blowpipe, distinguishing it from pure magnesite; second, its slow effervescence in acids. Besides these, its specific gravity is 2.8, hardness, 8.5; from calcspar it cannot be distinguished except by chemical analysis, as the two species blend almost completely with every intermediate stage of composition into either calc spar, or, what occurs in this locality, aragonite, similar in composition to it, or dolomite. The color of the last, however, is generally darker, and it cleaves less readily into its crystalline form, which is similar to calc spar, and of which it is harder, 3.5 to 3 of calc spar.

_Aragonite_.--This mineral, identical in composition with calc spar, but whose crystalline form is entirely different, occurs in this locality in veins hardly recognizable from the magnesite or dolomite, and running into dolomite. It is not abundant, and the veins are limited in extent; the only distinguishment it has from the dolomite, practically, is its fibrous structure, the fibers being brittle and very coarse. If examined with a powerful glass, they will be seen to be made up of modified long prisms. The specific gravity is over 2.9, hardness about 4, unless much weathered, when it becomes apparently less. There are some small veins at the north end of the walk, and in them excellent forms may be found by cutting into the veins.

_Brucite_.--This mineral occurs here in fair abundance, it being one of the principal localities for it in the United States, and where formerly extremely unique specimens were to be obtained. It has been pretty well exhausted, however, and the fine specimens are only to be obtained by digging into the veins of it in the rock, which are quite abundant on the south end of the walk, and, as I before noted, as deep as possible from the top of the veins, as it is a closely packed mineral not occurring in geodes, druses, etc. Two forms of it occur; the one, nemalite, is in fibers of a white to brown color resembling asbestos, but the fibers are brittle, and hardly as fine as a typical asbestos. It is packed in masses resembling the brucite, from which it only differs in breaking into fibers instead of plates, as I have explained in my description of that species (see Part II). They are both readily soluble in acids, with effervescence, and infusible but crumble to powder before the blowpipe, or at least become brittle; when rubbed in mass with a piece of iron, they phosphoresce with a yellow light; specific gravity, 2.4, hardness, 1.5 to 2. Its ready solubility in acids without effervescence at once distinguishes it from any mineral that it may resemble. The specimens of nemalite may be more readily obtained than the brucite but fine specimens of both may be obtained after finding a vein of it, by cutting away the rock, which is not hard to do, as it is in layers and masses packed together, and which maybe wedged out in large masses at a time with the cold chisel and hammer, perhaps at the rate of three or four cubic feet an hour for the first hour, and in rapidly decreasing rate as progress is made toward the unweathered rock and untouched brucite, etc.

_Serpentine_.--Fair specimens of this may be obtained of a dark oil green color, but not translucent or peculiarly perfect forms. The variety known as marmolite, which splits into thin leaves, is plentiful and often well worth removing.

_Chromic Iron_.--Crystals of this are included in the denser rock in great abundance; they are very small, seldom over a few lines in diameter, of an iron black color, of a regular octahedral form; sometimes large crystals may be found in place or in the disintegrated loose rock. I have seen them a half inch in diameter, and a half dozen in a small mass, thus forming an excellent cabinet specimen. By finding out by observation where they are the thickest in the rock, and cutting in at this point, more or less fine crystals may be obtained. This is readily found where they are so very abundant, near the equidistant points of the walk, that no difficulty should be encountered in so doing. These characteristics are interesting, and if large specimens cannot be obtained, any quantity of the small crystals may be split out, and, as a group, used for a representative at least. Before the blowpipe it is infusible, but if powdered, it slowly dissolves in the molten borax bead and yields a beautiful green globule. The specific gravity, which is generally unattainable, is about 4.5, and hardness 5 to 6. Its powder or small fragments are attracted by the magnet. A few small veins of this mineral are also to be found horizontally in the rock, and small masses may be obtained. They are very rare, however. I have seen numerous agates from this locality, but have not found them there myself. They may be looked for in the loose earth over the outcrop, or along the wall of the river. Our next locality is Paterson, N. J., or rather in a trip first to West Paterson by the D.L. & W. Railroad, Boonton branch, then back to Paterson proper, which is but a short distance, and then home by the Erie road, or, if an excursion ticket has been bought, on the D.L. & W, back from West Paterson. Garret Rock holds the minerals of Paterson, and although they are few in number, are very unique. The first is phrenite. This beautiful mineral occurs in geodes, or veins of them, near the surface of the basalt, which is the characteristic formation here, and lies on the red sandstone.

These veins are but two or three feet from the surface, and the ones from which the fine specimens are to be and have been obtained are exposed by the railroad cutting about a thousand feet north of the station at West Paterson, and on the west side of the rails. Near or below the beds is a small pile of debris, prominent by being the only one in the vicinity near the rails. In this loose rock and the veins which are by this description readily found and identified, they are about three inches in thickness, and in some places widen out into pockets even a foot in diameter They look like seams of a dark earth, with blotches of white or green matter where they are weathered, but are fresher in appearance inside. The rock, in the immediate vicinity of the veins, is soft, and may be readily broken out with the hammer of, if possible, a pick bar, and thus some of these geode cavities broken into, and much finer specimens obtained than in the vein proper. Considerable occurs scattered about in the before-mentioned pile of loose rock and debris, and if one does not prize it sufficiently to cut into the rock, taking the chances of lucky find, plenty may be obtained thus; but as it has been pretty thoroughly picked over where loose, it is much more satisfactory to obtain the fine specimens in place in the rock. When the bed for the railroad was being cut here, many fine specimens were obtained by those in the vicinity, and the natives of the place have it in abundance, and it may be obtained from many of them for a trifle, if one is not inclined to work it out. The mineral itself occurs in masses in the vein of a white, greenish white, or more or less dark green color. Sometimes yellowish crystals of it occur plentifully in short thick prisms, but the common form is that of round coralloid bunches, having a radiated structure within. Sometimes it is in masses made up of a structure resembling the leaves of a book slightly opened, and in nearly every shape and size. Crystals of the various forms may be well secured, and also the different colors from the deep green to the blue white, always remembering that true, perfect crystals are of more value than masses or attempted forms. The specific gravity is 2.8 to 2.9, hardness nearly 7 before the blowpipe; it readily fuses after intumescing; it dissolves in hot acid without gelatinizing, leaving a flaky residue.

_Datholite_.--This mineral is very abundant as inferior specimens, and frequently very fine ones may be obtained. They occur all around Garret Rock at the juncture of the basalt and red sandstone, in pockets, and as heavy druses. They are most abundant near the rock cuttings between West Paterson and Paterson, and may be cut out by patient labor. This is a long known and somewhat noted locality for datholite, and no difficulty need be experienced in obtaining plenty of fair specimens. Near them is the red sandstone, lying under the basalt, and baked to a scoriaceous cinder. Upon this is a layer of datholite in the form of a crystalline plate, and over or above this, either in the basalt or hanging down into cavities in the sandstone, are the crystals or geodes of datholite. Old spots are generally exhausted, and consequently every new comer has to hunt up new pockets, but as this is readily done, I will not expend further comment on the matter. The datholite, as in other localities, consists of groups of small colorless crystals. Hardness, about 5; specific gravity, 3. Before the blowpipe it intumesces and melts to a glassy globule coloring the flame green, and forms a jelly when boiled with the acids.

_Pectolite_--This mineral is also quite abundant in places, the greater part occurring with or near the phrenite before mentioned, in small masses generally more or less weathered, but in very fair specimens, which are about an inch in thickness. It is readily recognized by its peculiar appearance, which, I may again repeat, is in fibrous masses, these fibers being set together in radiated forms, and are quite tough and flexible, of a white color, and readily fused to a globule before the blowpipe.

_Feldspar_.--This mineral occurs strewn over the hill from place to place, and is peculiarly characterized by its lively flesh red color, quite different from the dull yellowish gray of that from Staten Island or Bergen Hill. Fine crystals of it are rather rare, but beautiful specimens of broken groups may be obtained in loose debris around the hill and in its center. I have not been able to locate the vein or veins from which it has come, but persistent search will probably reveal it, or it may be stumbled upon by accident. Some of the residents of the vicinity have some fine specimens, and it is possible that they can direct to a plentiful locality. However, some specimens are well worth a thorough search, and possess considerable value as mineralogieal specimens. The specific gravity of the mineral is 2.6, and it has a hardness of 6 before the blowpipe. It is with difficulty fused to a globule, more or less transparent. It occurs undoubtedly in veins in the basalt and near the surface of the outcrop As this locality has never before been mentioned as affording this species, it is fresh to the amateur and other mineralogists, and there need be no difficulty in obtaining some fine specimens. Its brilliant color distinguishes it from other minerals of the locality.

It is possible that some of the other zeolites as mentioned under Bergen Hill occur here, but I have not been able to find them. The reason may be that the rock is but little cut into, and consequently no new unaltered veins are exposed.

COPPER MINES, ARLINGTON, N. J.--A short distance north of this station, on the New York and Greenwood Lake Railroad, and about nine miles from Jersey City, is one of the cuttings into the deposits of copper which permeate many portions of the red sandstone of this and the allied districts in Connecticut and Massachusetts, and which have been so extensively worked further south at Somerville and New Brunswick, etc. There are quite a variety of copper minerals occurring in these mines, and as they differ but little in anything but abundance, I will describe this, the one nearest to New York City, as I promised in commencing these papers. The locality of this mine may be readily found, as it is near the old turnpike from Jersey City, along which the water-pipes or aqueduct, are laid. By taking the road directly opposite to the station at Arlington, walking north to its end, which is a short distance, then turning to the left along the road, there crossing and turning north up the next road joining this, until the turnpike is reached; this is then followed east for about a quarter-mile, passing occasional heaps in the road of green earth, until the head of a descent is reached, when we turn off into the field to the left, and there find the mine near the heaps of greenish rocks and ore scattered about, a distance from the station of about a mile and a half through a pleasing country. The entrance to the mine is to the right of the bank of white earth on the edge of, and in the east side of the hill; it is a tunnel more or less caved in, running in under the heaps of rock for some distance. It will not be necessary, even if it were safe, to venture into the mine, but all the specimens mentioned below may be obtained from the heaps of ore and rock outside, and in the outcrops in the east side of the hill, a little north of the mouth of the tunnel to the mine. The hammer and cold chisel will be necessary, and about three hours should be allowed to stay, taking the noon train from New York there, and the 5.09 P.M. train in return, or the 6.30 A.M. train from the city, and the 1.57 P.M. in return. This will give ample opportunity for the selection of specimens, and, if time is left, to visit the water works, etc.

_Green Malachite_.--This is the prominent mineral of the locality, and is conspicuous by its rich green color on all the rocks and in the outcrops. Fine specimens of it form excellent cabinet specimens. It should be in masses of good size, with a silky, divergent, fibrous structure, quite hard, and of a pure oil green color, for this purpose. Drused crystals of it are also very beautiful and abundant, but very minute. As the greater part of it is but a sixteenth or eighth of an inch in thickness, it may require some searching to secure large masses a quarter to a half-inch in thickness, but there was considerable, both in the rock, debris, and outcrop, remaining the last visit I made to the place a few months ago. The mineral is so characterized by its color and solubility in acid that a detailed description of it is unnecessary to serve to distinguish it. Its specific gravity is 4, and hardness about 4. It decrepitates before the blowpipe, but when fused with some borax in a small hollow on a piece of wood charcoal, gives a globule of copper. It readily dissolves in acids, with effervescence, as it is a carbonate of copper.

_Red Oxide of Copper_--This rather rare mineral is found in small quantities in this mine, or near it, in the debris or outcrop. Perfect crystals, which are of a dodecahedral or octahedral form, are fairly abundant. They are difficult to distinguish, as they are generally coated, or soiled at least, with malachite. The color proper is of a brownish red, and the hardness about 4, although sometimes, it is earthy, with an apparent hardness not over 2. The crystals are generally about a quarter of an inch to a half of an inch in diameter, and found inside the masses of malachite. When these are broken open, the red copper oxide is readily distinguished, and may be separated or brought into relief by carefully trimming away the malachite surrounding it as its gravity (6) is much greater than malachite. When a piece of the last is found which has a high gravity, it may be suspected and broken into, as this species is much more valuable and rarer than the malachite which is so abundant. It dissolves in acids like malachite, but without effervescence, if it be freed from that mineral, and acts the same before the blowpipe. Sometimes it may be found as an earthy substance, but is difficult to distinguish from the red sandstone accompanyit, which both varieties resemble, but which, not being soluble in the acids, find having the blowpipe reactions, is thus characterized. This red oxide of copper does not form a particularly showy cabinet specimen, but its rarity and value fully compensate for a search after it. I have found considerable of it here, and seen some little of it in place remaining.

_Chrysorolla_.--This mineral, very abundant in this locality, resembles malachite, but has a much bluer, lighter color, without the fibrous structure so often present in malachite, and seldom in masses, it only occurring as light druses and incrustations, some of which are very beautiful, and make very fine cabinet specimens. Its hardness is less than that of the other species, being under 3, and a specific gravity of only 2, but as it frequently occurs mixed with them, is difficult to distinguish. It does not dissolve in nitric acid, although that takes the characteristic green color of a solution of nitrate of copper, as from malachite or red oxide. This species is found all over this locality, and a fine drused mass of it will form an excellent memento of the trip.

_Copper Glance_.--This mineral is quite abundant in places here, but fine crystals, even small, as it all is, are rare. That which I have seen has been embedded in the loose rock above the mine, about a quarter inch in diameter, and more or less disguised by a green coating of chrysocolla. The color of the mineral itself is a glistening grayish lead color, resembling chromite somewhat in appearance, but the crystals of an entirely different shape, being highly modified or indistinct rhombic prisms. The specific gravity is over 5, and the hardness 4. Before the blowpipe on a piece of wood charcoal it gives off fumes of sulphur, fuses, boils, and finally leaves a globule of copper. In nitric acid it dissolves, but the sulphur in combination with it separates as a white powder. A steel knife blade placed in this solution receives a coating of copper known by its red color.

_Erubescite_--This mineral occurs massive in the rock here with the other copper minerals, and is of a yellowish red color, more or less tarnished to a light brown on its surface, Before the blowpipe on charcoal it fuses, burns, and affords a globule of copper and iron, which is attracted by the magnet. Its specific gravity is 5, hardness 3. It resembles somewhat the red oxide, but the low gravity, inferior hardness, lighter color, and blowpipe reaction distinguish it. These are the only copper minerals likely to be found at this mine, and the following table and note will show their characteristics:

Name. Speci- Hardness Action of Action of Color. Form.
fic Blowpipe Heat. Hot Nitric
Gravity. Acid.

Mala- From 4 From 3 Decrepitates, Dissolves Pure Oil Fibrous,
chite to 4.5 to 4 but fuses with with Green. massive,
borax to a effer- or in-
green bead. vescence crusting.

Red 6 From 3.5 On charcoal Dissolves A deep Modified
Oxide to 4 yields a without brownish crystals.
globule of effer- red.
copper. vescence

Chryso- From 2 From 2 Infusible. Partly Bright Incrus- colla to 2.3 to 3 soluble bluish tations. green.

Copper 5 From 2.5 Fumes of Copper Grayish Modified
Glance to 3 sulphur and a soluble, Lead. rhombic
globule of sulphur prisms.
copper deposits

Erube- 5 From 3 Fumes of Partly Yellowish Massive.
scite to 3.5 sulphur and soluble red or
magnetic tarnished.
globule.

Malachite is characterized by its color from Copper Glance and Red Oxide and Erubescite, and from Chrysocolla by the action of the acid, the fibrous structure and blowpipe reaction, gravity, and hardness.

Red Oxide is distinguished from Erubescite, which it alone resembles, by its darker color, higher specific gravity, and yielding a globule of pure copper.

Chrysocolla is characterized by its low specific gravity, light color, lack of fibrous structure, blowpipe reactions, and the acid.

Copper Glance is distinguished by its color, fumes of sulphur, and globule of copper.

Erubescite is distinguished from Red Oxide, which it alone resembles, by its lighter color, great solubility when pure, and yielding a magnetic globule before the blowpipe in the hollow of a piece of wood charcoal, which is used instead of platinum wire in this investigation.

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ENTOMOLOGY.

[Footnote: From the _American Naturalist_, November, 1882.]

THE BUCKEYE LEAF STEM BORER.--In our account of the proceedings of the entomological sub-section of the A.A.A.S., at the 1881 meeting (see _American Naturalist_, 1881, p. 1009), we gave a short abstract of Mr. E.W. Claypole's paper on the above insect, accepting the determination of the species as _Sericoris instrutana_, and mentioning the fact that the work of _Proteoteras æsculana_ Riley upon maple and buckeye was very similar. A letter recently received from Mr. Claypole, prior to sending his article to press, and some specimens which be had kindly submitted to us, permit of some corrections and definite statements. We have a single specimen in our collection, bred from a larva found feeding, in 1873, on the blossoms of buckeye, and identical with Mr. Claypole's specimens, which are in too poor condition for description or positive determination. With this material and with Mr Claypole's observations and our own notes, the following facts are established:

1st. We have _Proteoteras æsculana_ boring in the terminal green twigs of both maple and buckeye, in Missouri, and often producing a swelling or pseudo-gall. Exceptionally it works in the leaf-stalk. It also feeds on the samara of maple, as we reared the moth in June, 1881, from larvæ infesting these winged seeds that had been collected by Mr. A.J. Wethersby, of Cincinnati, O.

2d. We have an allied species, boring in the leaf-stalk of buckeye, in Ohio, as observed by Mr. Claypole. It bears some resemblance to _Proteoteras æsculana_, but differs from it in the following particulars, so far as can be ascertained from the poor material examined: The primaries are shorter and more acuminate at apex. Their general color is paler, with the dark markings less distinctly separated. No distinct tufts of scales or knobs appear, and the ocellated region is traversed by four or five dark longitudinal lines. It would be difficult to distinguish it from a rubbed and faded specimen of _æsculana_, were it not for the form of the wing, on which, however, one dare not count too confidently. It probably belongs to the same genus, and we would propose for it the name of _claypoleana_. The larva is distinguished from that of _æsculana_ by having the minute granulations of the skin smooth, whereas in the latter each granule has a minute sharp point.

3d. _Sericoris instrutana_ is a totally different insect. Hence our previous remarks as to the diversity of food-habit in this species have no force--_C.V.R._

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