Union, namely, first, it has proved to ocular demonstration the immense and varied undeveloped resources of the South; and second, by the interchange of ideas, opinions, and courtesies between intelligent and reflecting men of both sections which it afforded, the men of the North and of the South have learned to esteem each other more, to see the fallacy of the depreciative representations by unscrupulous politicians on both sides, by which they were respectively misled and estranged, and by dissipating the prejudices which made Georgia a terra incognita to the citizen of Massachusetts, and Maine a remote foreign country to the citizen of Georgia, to promote social and commercial intercourse between them, and finally exert a good influence in shaping the policy of the Federal Government.

The financial result of the enterprise may be stated in round numbers as follows:

Leaving for distribution to stockholders........ $20,000 When all the accounts are paid, it is not improbable that this apparent surplus will be reduced to zero. As none of the stockholders expected any return when they subscribed, and as they contributed with a view only to promote the success of a "World's Fair" at the South, the number of dollars to be returned to them is not a matter of any moment.

The buildings have been purchased for $25,000 by a stock company, who have also bought the land from the city of Atlanta for $15,000, with a view to establish immediately a cottonmill with not less than ten thousand spindles, with capacity of increase to twenty thousand, and with looms sufficient to weave the yarn from all the spindles employed. The name of the factory is to be the "Exposition Cotton Mills."

EYE-SIGHT, ITS DEFECTS AND TREATMENT. In no branch of practical science has there been greater advance in recent years than in that which pertains to the structure and functions of the human eye. Perhaps the most important conclusions lately reached are those which have definitely determined the method by which the vision is adapted to near and remote objects, and have ascertained the best means of preserving this power and of rectifying its deficiencies. The similitude of the eye to the camera of the photographer is quite familiar. It is well known that the rays of light proceeding from external objects enter the eye through the cornea or projecting horny substance in front, pass through the pupil, or opening in the iris, into the dark chamber of the eyeball, and are there brought together by means of a lens so as to form an inverted picture of the object on the retina at the back of

the chamber, which retina is a screen formed by the outspread fibers of the nerve that comes in from the brain. But while there is here a distinct analogy between the eye and the camera obscura, there are differences which are curious and important. In the photographer's instrument the rays are brought together on a flat surface, and no combination of lenses has yet been contrived to overcome completely the disadvantage of sharply defined details in the center, shading off into indistinctness about the edges of the picture. The maximum angle subtended by the field within which a tolerably clear image can be obtained is forty-four degrees, while in the eye, owing to the concave surface on which the rays are received, a field of one hundred and sixty degrees is obtained. The vision is not sharp over all this area, owing to the constitution and distribution of the nervefibers of the retina. In fact, the area of clearest sight is very restricted, but the relatively large surrounding surface of inferior sensitiveness serves the purpose of giving notice of the presence of objects in a wide field of vision, and guiding the eye to a closer scrutiny of them by means of its wonderful facility of movement. The optic nerve, which enters the back of the eye from the brain and constitutes the channel of visual impressions, is a white cord nearly one sixth of an inch in diameter, and is composed of fine threads, at least 250,000 in number. These spread out to form the retina, which is rather a mosaic pavement than a true net-work. The ends of some of the threads turn back upon themselves and form relatively thick cones of nerve-matter, while others terminate abruptly in rod-like ends. These are distributed somewhat irregularly, being closeset only at one central point directly back of the pupil. This is the one spot of supreme sensibility, and, being slightly depressed, is called the forea centralis, or central pit of the retina. It is constituted entirely of the cone-like terminations of the nerve-threads, relatively small in size and closely packed together, while around it is a less compact arrangement of the cone-like and rod-like terminations. Hence the visual picture is defined with consummate clearness only at this point, and presents a departure from the camera in the shape of an intensification of its chief defect, which in the eye thus becomes a part of its exquisite perfection, for the large area upon which the light falls affords a wide field of impression sufficiently sensitive to give notice of the presence of the objects which are reflected upon it, while the fine mechanism by which the eye is moved with a facility, quickness, and accuracy that are marvelous, brings the slight area of perfect vision to bear upon the particular object to be scrutinized or the different parts of that which is merely looked at. Therefore, we have practically combined perfect distinctness of the visual picture and a wide field for its reception. The camera fixes its glance upon a narrow field, and forms a picture with a clear center and

obscure or blurred outskirts. The eye sweeps its glance over a wide range, and forms clear pictures of every part of the field in such rapid succession as to receive the impression as a whole. This effect is, no doubt, promoted by the curious anomaly that, while the vibrations of light pass through a distance of 200,000 miles in a second, the nerve-influence passes from the eye to the brain at the comparatively sluggish rate of only two hundred feet in a second.

But the most important difference between the eye and the camera, and one that has only recently been fully understood, is to be found in the means employed for adjusting the instrument to the reception of light from near and remote objects. The lenses of the camera have each a constant focal length; that is, they bring parallel rays together at a certain distance from their own plane. If the rays are divergent when received, a part of the power of the lens is used up in bringing them parallel, and it must be farther from the screen, in order to concentrate the image distinctly upon it. So, if they are partly converged already, the lens must be nearer the screen. Hence, by moving the lens forward or back, the adjustment to near or distant objects is made. It was formerly supposed that the eye had some such power of elongating and compressing itself along the axis of vision, but this has been entirely disproved. Its mode of adjustment is entirely different. The eyeball is a sphere kept in shape by the fluids contained within its strong walls. These fluids serve a further purpose, not completely understood, in connection with the lens, in refracting the rays of light, but the lens alone contains the power of adjustment to distances. It is well established that there is a constant adjustment of the power of vision to the distance of objects. When the sight is fixed upon near objects, distant ones in the same direction can not be distinctly seen, and vice versa. Donders, the Dutch physiologist, furnishes a simple but effective illustration of this peculiarity of eye-sight. If a net is held between the eyes and a printed page, the attention may be fixed on either the net or the page, and either can be distinctly seen, but not both at once. The attention may be rapidly transferred from one to the other, and the process of adjustment will follow it. The change which takes place is wholly in the form of the crystalline lens, not in its position or the shape of the eye. This lens is suspended back of the iris and between the aqueous and vitreous humors. It is contained in a sort of sheath or shell of a slightly horny texture, which is set in a circular rim. This rim is stretched out in all directions and held firmly in place by seventy radiating elastic bands. These bands are about one fifth of an inch in length, and are attached at their extremities to the outer coat of the eye. They stretch the lens to its fullest circumference, maintaining a certain flatness which adapts it to the light from distant objects, so as to bring it to a perfect focus

on the retina. Connected with these elastic bands is a series of muscular fibers acting antagonistically to their elasticity; that is, when the muscles contract, the bands relax and allow the lens to bulge to a greater convexity, it having a natural tendency to do so when not stretched out. When the muscular fibers are brought into action so as to increase the convexity of the lens, the vision is adapted to near objects; and it is the constant play of the elastic bands and muscular fibers, together with the ready movement of the eye, that adapts the sight to objects at all ranges of distance and direction. The expansion and contraction of the iris, so as to admit more or less light at once, add effectiveness to the marvelous contrivance by which the impressions of the external world are conveyed to the brain. It is manifest that the eye must be in constant action during the hours of wakefulness, and that its delicate mechanism is subjected to a strain from which the only absolute rest is sleep or complete darkness.

These conclusions regarding the method by which the power of vision is adjusted to various distances have been thoroughly established by the investigations of Sanson, Langenbeck, Cramer, and Helmholtz, and are adopted by R. Brudenell Carter, one of the latest authorities on eye-sight. Professor Helmholtz has contrived an instrument for observing and measuring the various curvatures of the crystalline lens, which is turned to practical account in producing optical compensations for defective sight. This perfected knowledge of the structure of the eye has in fact had an important effect upon the treatment of defective vision. The crystalline lens is constructed out of a series of flattened fibers of albuminous substance, grouped in symmetrical loops around six separate axes, and connected together at their edges by interlocking teeth. The transparent mass is soft and pliable in youth, but it gradually grows denser with advancing years. This interferes with the facility with which it can be adapted to near vision, and is the cause of failing eye-sight. In early life the lens can be curved easily so as to bring objects not more than four and a half inches from the eye clearly into view, but at the age of forty it can not form a clear picture of objects nearer than nine inches. At fifty the point of nearest sight is removed to thirteen inches, at sixty to twenty-six inches, and usually at seventy all power of accommodation is practically gone. The lens retains the uniform contour adapted to distant objects, while it transmits the light with a somewhat impaired degree of perfection. The remedy for this is to supply the needed power of refraction by artificial lenses placed before the eye. By this means the power of clear vision for a certain fixed but convenient minimum of distance is completely restored. The artificial lenses should vary in convexity according to the needs of the eye. Mr. Brudenell Carter dwells with considerable

emphasis in Lis recent work on "Eye-sight, Good and Bad," on the inexpediency of postponing the use of artificial aids when they are needed. The failing of sight for near objects is the result of a loss of adjustability in the crystalline lens which can never be regained, and the loss will be accelerated by overstraining the eye. Spectacles should be resorted to as soon as they are needed, and should be always carefully adjusted to the actual need. Mr. Carter says: "It can not be too generally understood that spectacles, instead of being a nuisance or an incumbrance, or an evidence of bad sight, are to the far-sighted a luxury beyond description, clearing outlines which were beginning to be shadowy, brightening colors which were beginning to fade, intensifying the light reflected from objects by permitting them to be brought closer to the eyes, and instantly restoring near vision to a point from which, for ten or a dozen years previously, it had been slowly and imperceptibly, but steadily, declining. This return to juvenility of sight is one of the most agreeable experiences of middle age; and the proper principle, therefore, is to recognize loss of near sight early, and to give optical help liberally, usually commencing with lenses of +1.25 or + 1.50, so as to render the muscles of accommodation not only able to perform their tasks, but able to perform them easily. When, as will happen after a while in consequence of the steady decline of accommodation, yet more power is required, the glasses may be strengthened by from half a dioptric to a dioptric at a time, and the stronger glasses should at first be taken into use by artificial light; the original pair, as long as they are found sufficient for this purpose, being still worn in the day-time." Mr. Carter and Dr. Harlan both strongly recommend, whether for the failure of near vision or for near-sightedness, the use of spectacles in preference to eyeglasses, which are less perfectly adjusted before the eyes and less steadily held in place.

Short sight is a defect of vision which arises from no natural or progressive modification of the organism of the eye, but it is often aggravated and indeed produced by the bad conditions under which the eyes are used. The organic cause of myopia is a too great depth of the eyeball, which causes the sharp image of an object to be formed in front of the retina instead of directly upon it. Eyes that are subject to this defect have a very sharp vision for objects held quite close to them, but at a little distance the outlines become blurred and the details indistinct. The remedy is spectacles with concave glasses, which should be adopted promptly when the need is discovered, because by constant straining of the eye its defect will become aggravated, even if an actually diseased condition is not induced. The organic peculiarity which is the cause of near-sightedness is often inherited, and some children are myopic at birth, but in general it is only the tendency that is congenital. This may be held in check,

VOL. XXI.-18 A

or it may be accelerated, and very often nearsightedness originates in later life. It is most prevalent where civilization is farthest advanced, is more common in old than in new communities, in cities than in the country, among brain-workers and cultivated people than among laborers and the illiterate. There is a general agreement among authorities that a great development or increase of it takes place during school-life, and the result is largely due to preventable causes. "There is no longer any room for doubt," says Mr. Brudenell Carter, "that badly-lighted and badly-fitted schools form a great machinery for the development of myopia, and it is probable that this machinery, where, as in Germany, it has for a long time been in unchecked operation, may have an important influence upon the form of the eyeball, which will be inherited by large numbers of the population." Dr. Harlan declares that "it has been positively established by careful and extensive statistics that short sight is more frequently, if not almost exclusively, developed during school-life." Dr. Colin, of Breslau, reported, as the result of an examination of 10,000 school-children, that 1,000 of them were near-sighted, and he found that the defect increased numerically as the pupil advanced through the different grades of the schools. He found 6.7 per cent of myopia in the elementary, 103 in the intermediate, 19-7 in the high schools, and 26-2 in the gymnasia. Similar investigations with like results have been made by Dr. Erismann, in Russia, and by Drs. Agnew, Loring, and Lundy, in the United States. Dr. Lundy, of Detroit, found an increase of near-sightedness in a twelve years' course at school from 0 at the beginning to 12 per cent in the highest grade, a progressive development of 1 per cent a year. Imperfect light, impure air, bad construction and arrangement of desks and seats, and badlyprinted books, are among the causes assigned. Dr. Donders, of Utrecht, declares that "the foundation of near-sightedness is mainly laid in schools, where, by imperfect light, the pupils read bad print or write with pale ink." Another cause of injury to the eyes, as well as the general health, is the admission to schools, and too close confinement there, of children at a too early age.

There is a form of imperfect vision known as astigmatism, which is caused by a more or less irregular curvature of the front part of the eye. When it exists to any marked degree, vertical and horizontal lines can not be distinguished with equal clearness. It is in some measure corrected by the use of glasses with a cylindrical instead of a spherical curvature. A structural defect of the eye, in the treatment of which great progress has been made, is that known as cataract, in which the crystalline lens condenses and thickens until it becomes impermeable by light. It is now very effectually treated by the complete removal of the lens, the place of which is supplied by a

properly adjusted lens of glass in front of the eye. This, of course, is absolutely without the power of accommodation, and different glasses have to be used for seeing at different distances. Professor Helmholtz adopts the conclusion that the perfection of the eye depends not upon the excellence of its construction as an optical instrument, but upon the manner in which it is used. The chromatic aberration of its humors, the astigmatism of its irregular contours, the blind-gaps of its nerve-screen, the imperfect transparency of its refractive media, the interposition of blood-vessels in front of the retinal membrane, the narrow limitation of the area of sharp definition, and the prevalent blurring of the lateral parts of the field, are all conditions that must be classed as optical imperfections. Yet every one of these imperfections is so counteracted and neutralized in the use of the organ under the plan of the employment of two eyes, and under the expedient of the rapid transference of the attention to different parts of the image, that it is actually unrecognized as a defect, and undiscovered until the most refined powers of scientific investigation have been brought to bear for its detection.

There are many injuries to which the eye is subject, and many conditions having an important bearing on the preservation of good eyesight, besides those mentioned in connection with structural or induced defects of form. It is Mr. Carter's belief that a very large proportion of what is generally regarded as congenital blindness is really caused after birth by ignorant or careless treatment. He puts the proportion as high as ninety-nine cases in one hundred. The eyes of new-born infants are doubtless extremely sensitive to the effects of light and temperature, and are imperfectly shielded by nature. "From the imperfect development of the bones of the infant skull," says Mr. Carter, "the eyes are placed, so to speak, on the surface, instead of being in hollows; the eyebrows and eyelashes are short, thin, and pale; the eyelids are almost transparent, and the irides are imperfectly furnished

FALKLAND ISLANDS. These islands form a group in the South Atlantic Ocean, about two hundred and fifty miles northeast of Tierra del Fuego. The number of islands is about two hundred, but only two of them are of any considerable size. Their whole superficies is reckoned at 5,000,000 acres. A few years ago penguins and sea-lions chiefly occupied their shores; but of late the English Government has encouraged emigration to them, and now numberless sheep fatten on their grass. These yield to their owners such an abundance of wool that it has become an article of exportation growing yearly in impor

with opaque pigment. In the first weeks of life, moreover, infants are unable to shelter themselves from dazzling light by changing the position of the head." Protection from too strong light and from sudden or violent changes either of light or temperature, proper attention to cleanliness and ventilation, and the intelligent treatment of purulent ophthalmia when it shows itself, would in his opinion prevent a very large proportion of the cases of blindness generally believed to be congenital.

Mr.

Artificial illumination is more trying to the eyes than daylight, but, when its use is necessary, the risk of injury may be reduced to a minimum. There is little choice between oiland gas-light of a similar illuminating power. Mr. Carter remarks, "The best illumination for all purposes of close work is that of a Silber Argand burner, it matters not whether for gas or oil, placed to the left front of the worker, a little above the level of the eyes, fitted with a shade to reflect light upon the table and to intercept it above, and with the addition of an alum screen when the heat is objectionable." When several lights are used, they should be grouped together, as all cross-lights are distressing to the eye. Carter recommends that the least exacting kind of work should be done in the evening or at night; and, for literary men, reading and study by day and writing at night is the best arrangement. Reading in cars or other moving conveyances, and the close use of the eyes by dim or unsteady light, are universally condemned. Smoke is injurious to the eyes and eyelids, but, aside from its external irritating effect, Mr. Carter does not agree with some older writers in the opinion that tobaccosmoking produces any material injury to the eyes or optic nerves. According to the same authority, colored glasses should not be used except under competent surgical advice. But where protection is desired for healthy eyes from the glare of a strong light, or from reflection on snow or water, pale cobalt-blue or neutral gray is to be preferred to green or very dark glasses.

tance. No other English colony has relatively made such progress during the last ten years. The population has doubled and the production has quadrupled. According to the statements of the English colonial office, the imports, which in 1867 amounted to £20,590, had in 1878 increased to £35,040. The exports, amounting in 1867 to £15,460, had increased in 1878 to £55,470. The population in 1867 was 705, and in 1878 it had increased to 1,394. The value of the exports relatively to the number of the inhabitants is £40 to each; while in Australia it is £19 to each, and in the United States it is £4. The balance of trade in favor

of the colony is equivalent to £15 for each inhabitant.

FERTILIZERS. The system of agriculture which consists in removing crops without restoring the plant-food they take from the soil, and which Liebig aptly called Raubbau (robbery-culture), has already reduced the soil of our older States to the condition where it must be fertilized or abandoned; where not only the most careful tillage, and husbanding of the manurial resources of the farm, but also the importation of plant-food from outside, are requisite to the restoration of fertility. Guano, phosphates, potash salts, and the like, have become with us, as in Europe, indispensable to successful agriculture.

Every one of the Atlantic, and many of the Middle States, employ large quantities of commercial fertilizers. Their use is extending to the prairies of Indiana and Illinois; and even in Kansas experiments are being made with them on soil stated to be "worn out with long cropping." Single towns in Connecticut are said to expend $20,000 per annum in artificial manures, and the State of Georgia imports annually some $5,000,000 worth of plantfood, in the form of phosphates, guano, potash salts, and the like, to restore fertility to her soils. The amounts of these materials sent out from the central markets in the spring of 1881 were so great as to make, in some places, a railroad blockade. The Commissioner of Immigration of Georgia says: "It is frequently stated that the immense increase of the cotton-crop since the war over that prior to 1860 is due to emancipation only. A most important factor in bringing this about has been the very general use of commercial fertilizers." The rapid improvement of Southern agriculture has been made practicable by various material agencies, of which this is one of the chief. Not freedom alone, but freedom and superphosphates, are giving us the "New South."

How important a factor of the agricultural progress of the country commercial fertilizers have become is illustrated by the following figures, partly official and partly general estimates, but doubtless reasonably correct:

The Commissioner of Agriculture of the State of Georgia reports that the number of tons of commercial fertilizers inspected in that State in 1881 was 152,464, from which the State received $76,232 (a tax of fifty cents being levied upon each ton consumed in Georgia). Dr. Dabney, Director of the Agricultural Experiment Station of North Carolina, reports, under date of December 15, 1881, that 50,000 tons were consumed in 1878, 60,000 tons in 1879, and 80,000 tons in 1880; and that "the sales this year (1881) will slightly exceed this last amount."

It is estimated that Virginia consumes over 40,000 tons; Pennsylvania, over 50,000 tons; New Jersey, over 20,000 tons; New York, over 35,000 tons; Ohio, over 15,000 tons; New England, over 50,000 tons; and the use

of fertilizers is rapidly increasing toward the Mississippi Valley, and through Michigan, Indiana, and Kentucky. The consumption in the Atlantic and Middle States is estimated at not less than 500,000 tons, or about $20,000,000 worth. Thousands of farmers, therefore, must be using fertilizers successfully, else why this constantly increasing consumption?

The term commercial fertilizers properly applies "to those articles occurring as natural deposits, like guano and Chili saltpeter; or manipulated in some way, like dried blood and fish-scrap; or regularly manufactured, like superphosphates and potash salts, which are powerful fertilizers, are expensive in comparison with farm manure, and are regularly quoted in our market reports."

The history of the trade in commercial fertilizers dates back not more than about forty years. The value of bone, fish, and even of superphosphate of lime, however, was recognized long ago in farm practice. "The first settlers in this country learned of the aborigines on the coast that a fish, planted in each hill of maize, greatly increased the crop; bones were used as manure in England, to some extent, early in this century, and superphosphate of lime was made and applied by Sir James Murray, in England, as early as 1817."

In 1840 the first cargo of Peruvian guano was shipped to Europe. This date may be said to mark the beginning of the use of commercal fertilizers in agriculture. In the same year appeared Liebig's "Chemistry, in its Applications to Physiology and Agriculture," which book, with his other contributions to the subject, made the beginning of that movement which has created a science of agriculture, and has enabled the art of agriculture to meet the demands of modern life.

It is a not uninteresting coincidence that two movements of such moment for agriculture, artificial supply of plant-food to soils and the rational application of science to their culture, should have received their first great impetus at the same time. The ingredients to which the efficacy of the more common commercial fertilizers is mainly due are three-nitrogen, phosphoric acid, and potash. Among the more important sources of these materials in the American markets may be mentioned:

Nitrogen (ammonia).-The chief sources of nitrogen are: nitrate of soda and sulphate of ammonia, which supply nitrogen without phosphoric acid or potash; the various forms of slaughter-house refuse, dried blood, azotin, tankings, etc., which contain nitrogen with some phosphoric acid; and fish-scrap and Peruvian guano, which furnish both these ingredients in considerable quantities, the latter containing also some potash.

Phosphoric Acid.-The most important phosphatic materials are: bone-black, Canadian apatite, Navassa and South Carolina phosphates, and sundry "rock" or "washed" guanos, as Curaçoa and Orchilla, which supply