intrinsic value of the human mind as a thinking machine, but themselves and their fellows? It is a universally received maxim that no man is a competent judge of his own capabilities, that no man can speak with impartiality upon the customs of his own country, as compared with those of foreign countries; is it then to be supposed that human beings, however eminent for sagacity and wisdom, can form any fair and unprejudiced assessment of the relative range and amplitude of their own intellectual powers? Sir J. Lubbock, in his abovementioned work, points out many resemblances between human and formic nature. Both men and ants are social creatures, both make slaves, and domesticate animals. Yet who can doubt that a Treatise upon Formic Nature, written by a learned ant, would be filled with. the most exalted assumptions of formic superiority? Let the parallel stand for what it is worth, it is needless to point the moral. I will now proceed one step further. The human brain, whatever its capabilities, can only receive its knowledge of the appearance of external Nature through the agency of the eye. The stars, for instance, would not exist to us if we did not see them; and it is by means of contrivances to enlarge and extend the power of the eye that the most important advances have been made in our acquaintance with the universe. It is clearly, then, vitally important before all things, that our eye should be a perfect contrivance, a faultless instrument. To show how far this is from being the case, it is only necessary to quote the words of the greatest authority upon the subject, Professor Helmholtz. "I need not call to mind," he says, in his address at Innspruck," the startling and unexpected results of ophthalmometry and optical research which have proved the eye to be a by no means more perfect instrument of research than those constructed by human. hands, but on the contrary to exhibit, in addition to the faults inseparable from any dioptric instrument, others that in an artificial instrument we should severely condemn," &c. The faultiness and coarseness of construction, then, of the medium by which alone. visual impressions can be conveyed to the brain, of itself constitutes a natural limit to our powers of observation, an inherent defect, which skill and experience may diminish, but cannot eradicate. And that which has been said of the eye, applies in a greater or less degree to all the senses. We find, then, from all these causes, that there must be a very circumscribed area to all the empirical knowledge which can be acquired by man. He may form bold hypotheses, he may devise startling theories, which in a rough and ready way fall in with and account for certain facts; but the progress of research and fresh accumulations of experiments will generally in the end tend to prove * See also his Lecture on the Eye as an Optical Instrument, passim. that even those theories, which are sufficiently established to be inscribed as laws of Nature, are but crude and inaccurate approximations to truth. That such has been the case with many theories which once enjoyed a considerable reputation we know. Stahl's theory of phlogiston, Prout's hypothesis that the atomic weights of elementary substances were simple multiples of hydrogen, the corpuscular theory of light, the one-fluid theory of electricity, among those of more modern times, have had their day, have been found wanting, and are discarded. Bode's law, which led to the discovery of the asteroids, has been confuted by the discovery of Neptune; and even the plausible nebular hypothesis of the origin of the universe, as conceived by Kant and worked out by Laplace, is at length threatened with discredit through the awkward discovery that one of the newly found satellites of Mars revolves round its primary in a third of the time in which the latter turns on its axis. These and other failures. equally conspicuous should teach us to receive even the most confidently asserted and universally received theories of our own time with suspicious reserve. "Chi non sa niente, non dubita di niente." Popular scientific lecturers and writers have acquired in these days a very unpleasant habit of dogmatism. They assume an air of infal libility, and express in no measured language their mean opinion of those who do not swallow a new-fangled doctrine, however unpalatable or distasteful, without making one wry face. Science is declared to be the unerring guide to all truth, and its teachers-well, “New professor is but old prophet writ large." Not such is the spirit of truly great discoverers and thinkers, men of the stamp of Newton and of Darwin; such men are always molest aud reserved in their assertions, but the mantle of the master docs not always descend upon the disciple. All the past history of scientific progress conspires to invalidate any such infallible claims. What it teaches us is, that every hypothesis, which successfully accounts for many complicated phenomena, probably contains some, possibly a very large element of truth, almost certainly not the whole truth. Even the law of gravitation, extraor dinary though the confirmations be which it has received, notably by the discovery of Neptune, is perhaps only a very near approximation to the actual attracting force, which may be of a much less simple character than the product of the masses divided by the inverse square of the distance, and involve minute terms of higher orders. The complex spectra, again, of the so-called elementary bodies seems to suggest that there are many of them at any rate compound and not simple substances. In fact, what are our grounds for calling them simple substances? Why, because under the very limited conditions of pressure and temperature to which we can subject them, they refuse to be decomposed. Who knows what might be the result of applying to them the utterly different pressures and temperatures existing in other parts of the universe? Or take the doctrine of the Conservation of Energy, a doctrine which is now received as a kind of scientific axiom, and which is certainly supported by much direct proof and powerful argument. But surely it will be time for this doctrine to claim our unreserved assent, when at least some attempt has been made to explain the cause and the nature of known forces, a subject of which we know absolutely nothing. The theory, too, of Dissipation of Energy, put forth by Sir W. Thomson, is a curious corollary upon the main theory. According to Thomson all forms of energy are continually dissipating themselves throughout space in the form of heat; so that ultimately all energy would be represented by a uniform temperature, henceforth changeless and eternal, because incapable of transformation. Is it impertinent to ask whether energy, thus perfectly stagnant, can be said to be existent at all? Let us pass on. No branch of science has during the past half century advanced with more rapid strides than geology, and none has based upon its discoveries a more imposing structure of inference and deduction. Now, the greatest authorities upon this subject require us to believe, as a cardinal doctrine, that the ordinary slowly working forces of degradation, now in operation upon the earth, are sufficient to account for the immense gcological changes that have taken place in past ages, and consequently assign countless millions of years for their gradual accomplishment. Yet Professor Tait points out that this assumption is in irreconcilable conflict with the conclusions of physical science, and that "a limit of something like ten million" years is the utmost that can be given to geologists for their speculations as to the history even of the lowest orders of fossils. "But I daresay," he adds, "many of you are acquainted with the speculations of Lyell and others, especially of Darwin, who tell us that even for a comparatively brief portion of recent geological history three hundred million years will not suffice. We say, So much the worse for geology as interpreted at present by its chief authorities." "Non nostrum tantas componere lites." It is sufficient for our purpose to point out such a yawning discrepancy between rival theories of equal authority. Let us There are many other subjects which invite criticism. select the undulatory theory of light. This theory has not only been successful in accounting for known optical facts, but has actually predicted such intricate and unexpected phenomena as conical refraction and circular polarization after two reflections in a rhomb. * Tait, "Recent Advances in Physical Science," p. 167. But, in addition to many minor points of difficulty in its path, this favoured theory has encountered an obstacle of the first order. It has not been able satisfactorily to explain the "dispersion of light." Yet, if it cannot, it fails to satisfy a crucial test. To account for the "dispersion of light," it is necessary to assume that rays of different colours are propagated with different velocities. Now, not only is such an assumption contrary to the analogy presented by sounds different in pitch, which are heard simultaneously, but is opposed to astronomical experience. When one of Jupiter's satellites, to take one instance, suddenly emerges from eclipse, it should rapidly assume in succession the different spectral colours, if the several chromatic rays travel with different velocities. Such, however, is confessedly not the case. Now a physical theory differs from a rule of syntax-it admits of no exceptions. A single discrepancy with proved fact is sufficient to condemn it : "It is the little rift within the lute, That by and by will make the music mute, It is scarcely worth while to examine seriously those more fanciful hypotheses by which the mind of man at once exhibits its ingenuity and its helplessness in the presence of the more recondite problems of Nature. The human imagination struggles in vain to account for the phenomena of light, heat, electricity, magnetism, and chemical action, by inventing supposititious media of action. Despite inconceivable attributes and contradictory characteristics, these fictitious æthers remain proof against professorial jugglery, and refuse to perform the impossible feats required from them. Such ingenious conceptions as the "vortex-ring" theory of Thomson, or the "ultra-mundane corpuscles" of Le Sage, justly excite our admiration, simply as intellectual achievements, although the one fails to show that gaseous moloecules can be considered perfectly elastic, and the ther to explain action at a distance, for the simple reason that the primary assumptions in either case are inconceivable It is not necessary for me to proceed further with my argument, or to enter into greater detail. To do so would require more space than is at my disposal. My object in writing has not been to criticize scientific theories in any unfriendly spirit. Far be it from me to disparage the extraordinary advances that have been made in these our own days, whether we look at them from an intellectual or material point of view. Such undoubted progress, however, renders it the less excusable that mere conjectures and guesses at truth should be presented to the unscientific public by men of authority, who themselves know better, or ought to know better, as doctrines established by positive and irrefutable evidence. Such conduct can only end in throwing discredit, not upon science, but upon its interpreters. GEORGE EDMUNDSON. LAND TENURE AND TAXATION IN GYPT, as every one knows, is essentially an agricultural country. and both for the necessities of life and for any superfluous wealth, its inhabitants are altogether dependent upon the produce of the soil. The agrarian laws and institutions of such a country are consequently matters of vital importance, a correct knowledge of which is indispensable to those seeking to advance the interests of its people. There are, nevertheless, no subjects connected with Egypt less understood, or upon which the public of this and other nations of Europe are so destitute of sources of information. Most of us have heard that Egypt exists under a system, common to the generality of Eastern countries, inherited from a remote antiquity, and transmitted practically unchanged down to the present generation. But no one, so far as I am aware, has called attention to the fact that, within the memory of men still in the prime of life, the germs of a change of the most important character silently came into existence, and that, whether for good or for evil, the traditional land system of Egypt is finally undergoing a revolution-if indeed that revolution must not be spoken of as completed—the importance of which it is impossible to exaggerate. According to the immemorial institutions and traditions of Egypt the land is the absolute property of the nation, represented by the State, and its cultivators occupy a position in most respects analogous to that of an English tenant. It is true that the idea of private property in land is not wholly unknown. Such lands, styled Amlák, have at various times been held by private individuals, whose titles were acquired by purchase from the Administration of the Beyt al Mál, the |