as known the Nelson has neither rock, nor shoal, nor excessive rapid to interfere with its navigation by properly constructed steamers. Its even gradual slope of twenty inches to the mile is not more than is constantly and safely worked on other American rivers. The Upper Missouri and Yellowstone, with far worse water to contend with, were constantly navigated in 1877 by twenty-seven steamers; whilst the old Danube at its Iron Gate has water quite as strong to contend with, and not half the breadth and depth of water for a vessel to pick her way in. The question remains to be solved whether this river is really available or not for ocean steamers to work through to the lake above, and, if not, whether the lake steamers can be trusted to bring their cargoes down with a certainty of being able to reascend again. The outlet of Nelson River on salt water forms itself a fine natural safe harbour, a mile wide, and with any depth of water. It is called Port Nelson, and not very far from it is the old York Factory, for a long time the headquarters of the Hudson's Bay Company, and from which, for the last two hundred years, from two to five vessels have annually sailed for England, and not unfrequently under the convoy of a man-of-war. Port Nelson, although situated in 93° of west longitude, in the very heart of the continent, is eighty miles nearer to Liverpool than New York is. For four certainly, probably for five, months in the year it is as clear of ice as any other of the North Atlantic ports. There is no question about its accessibility for ordinary ocean steamers from June to October, and it only remains to be proved whether these same vessels cannot force their way up the great Nelson River, and load their cargoes directly at the mouth of the Saskatchewan, the Red River, or the Winnepeg, in the very centre and heart of this great wheat-field of the North-West, where 200,000,000 acres now await the advent of the farmer to be rapidly brought into cultivation.

At the present rate of immigration and the rapid reclamation of this easily cultivated land, it is by no means unlikely that within the next two years 2,000,000 acres of this prairie will be under wheat cultivation, and this probably will be doubled within five years from the present time. This means an addition to the wheat products of the world of 100,000,000 bushels, which may be increased almost indefinitely. The exports of all America to the United Kingdom from the 11th of September, 1877, to the 11th of May, 1878-that is the eight shipping monthsfrom Boston, New York, Montreal, and all Eastern and Canadian ports, and from San Francisco to the 2nd of the month, were as under :

Flour.....

Wheat.

1,427,584 bushels .44,516,823 bushels .45,312,427

Maize Corn......... which, with some other cereals, may be put down as equal to 100,000,000 bushels, an amount which, large as it is, is not more than may be expected within the next few years to be the annual production of this new wheat-field of the Winnepeg watershed. Even last year the volume of cereals going forward was considerably more than the ordinary

quantity. From the 1st of January 1878 the receipts and shipments of grain at the principal Western depôts were 50 per cent. in advance of those for the same period last year, and the most noticeable increase was in wheat, which was more than double in quantity.

The corn export of Russia during 1877, notwithstanding the closing of the southern ports, amounted to 188,625,000 bushels, or 42,567,000 more than in 1876. The large increase was in shipments from the Baltic, which were 94,387,000 in 1877 against 57,724,000 in 1876. This is the largest yield from Russia for some years, but it is only the product of 4 per cent. of the Winnepeg wheat-field.

The total importation of wheat has not averaged for the whole of the United Kingdom, reducing flour to its equivalent of wheat, more than 100,000,000 bushels per annum-the produce of only 4,000,000 acres of this land, the sales only of six months in the Red River valley alone. The influence of the opening up of this new district cannot but have, therefore, a most important effect upon the supply of the English market; it will make the mother country entirely independent of foreign supply, and it is to be hoped that it will form another bond that shall draw more closely together the many ties that already lock Great Britain to her largest and most promising colony.

T. T. VERNON SMITH, in Nineteenth Century.

GENERIC IMAGES.

In the pre-scientific stage of every branch of knowledge, the prevalent notions of phenomena are mainly founded on general impressions. But when that stage is passed, and the phenomena are submitted to measurement and numbering, very many of the notions that were derived from general impressions are discovered to be wrong, even absurdly so. I do not speak only of such matters as astrology and alchemy, but of those also with which most persons are acquainted. Think of the nonsense spoken every day about signs of coming weather, in connection, for example, with the phases of the moon, and firmly believed in by many respectable people. Think of the ideas about chance, held by those who are unacquainted with the theory of probabilities. Think of the notions entertained on heredity before the days of Darwin. Think of the ridiculous nostrums that have been prescribed for common ailments by gifted and experienced practitioners, the merits of which have been also vaunted by the invalids who tried them. It is not necessary to go into more detail in illustration of the fallacies of popular generalisations. The list of them is endless; they are to be abundantly found, as already observed, in every branch of knowlege, before it has been seized in the firm and sure grasp of processes that depend upon exact measurement and number. That popular notions are habitually incorrect may be taken for granted, and my purpose in this memoir is to explain one cause of their incorrect

ness.

I propose to call attention to an error in the operations of the mind, whenever it blends memories together, and to show why the brain is a faulty apparatus for elaborating general impressions. I shall argue that we have no means of correcting its necessarily fallacious results, except by picking them to pieces, and going back to the facts whence the general impressions were derived, and by dealing with those facts on true statistical principles. Thus if we hear that some medical nostrum is highly reputed, or that some particular appearance is an excellent prognostic of coming weather, our first step towards investigating the truth is not to ask whether the belief is firmly held, or of old standing, or shared by many, but to obtain a considerable number of instances and to set off the failures against the successes.

The general impressions and ideas to which I refer guide the great majority of our everyday actions. We have a general impression that the day looks rainy, and we take an umbrella. We find ourselves in a railway carriage with a person who looks sociably inclined and agreeable, and we accost him accordingly.

In an infinity of cases like these, the opinion on which we act has not been formed by any process of reasoning; neither has it been made by considering what similar experiences we have had, and counting their results on this side and on that, but it is the effect of blending together a large number of similar incidents. These blended memories are the subject of my present memoir. I shall try to prove that blended memories are strictly analogous to blended pictures, of which I have produced many specimens by combining actual portraits together; and I shall explain the peculiarities of the images by those of the portraits; then I shall show that the brain is incompetent to blend images in their right proportions. My conclusion will be that our unreasoned impressions are of necessity fertile sources of superstition and fallacy from which the child and the savage are never free, and with which all branches of knowledge are largely tainted in their pre-scientific stage. Lastly, that it is only by the strict methods of scientific inquiry, namely by measurement and number, that these fallacies can be cleared away and the truth discovered.

The physiological aspect of simple and blended memories is intelligible enough in its broad outlines, and may be briefly described. Whenever any group of brain elements has been excited through an impression of one of the senses, it becomes, so to speak, tender and liable to become again excited, under the influence of other kinds of stimuli. Whatever may be the cause of any new excitation, the result of its reproduction is to create an imaginary sense-impression, similar to that by which the first excitation had been caused; and this we call memory. Blended memories must necessarily follow the excitation of many associated groups of brain elements, under the influence of a stimulus that sets them simultaneously in action.

Faint memories are particularly apt to blend together, and they often defy analysis afterwards. We are shown some picture of mountain and lake, from a country we have never visited, yet it seems familiar

to us; it accords with what we have seen dozens of times in Scotland or Switzerland or elsewhere, but our memories are confused and obscure, and we cannot wholly disentangle the incidents to which they relate.

Memories that are extremely vivid may at the same time be very mobile, and capable of blending together. Much instruction on these. maters can be derived from those who possess the power of what is called the visualising faculty, in a high degree. The objects of their memory are conspicuous images; they can retain them for a long time before the eye of their mind, they can dismiss or change them at will, and they can, if they please, subject them to careful examination from every side. I do not know any faculty that varies so much as this in different persons. None can vary more, because its range lies between perfection and nothingness. It is sometimes absolutely deficient, for there are persons who never see mental images even in dreams, and there are others who are said to have lost the power of seeing them. I need not speak of cases where the visualising power is feeble, as they are common. Many are like those to whom St. James alludes when he speaks of a man beholding his natural face in a glass, who beholdeth himself and goeth his way, and straightway forgetteth what manner of man he was.' It will be more to my point to show how perfect the visualising faculty sometimes is, at the same time that the images may be moved with the utmost facility in the field of the mind's eye, which is a first step towards their blending together. Out of the many available instances I will only quote one, and will choose that one chiefly because it has recently excited some public attention. There appeared in the Spectator, of December 28 last, two very interesting letters concerning a peculiar form of visualising possessed by the late Mr. Bidder, the engineer, known in early life as the 'calculating boy,' and this gift is possessed in a high though less degree by several of his descendants. Thus the eldest son, Mr. George Bidder, Q.C., can mentally multiply fifteen figures by fifteen, though not with the same precision and rapidity as his father. One of the two letters is from Mr. Bidder's friend, Professor Elliot, who writes thus:

If he saw or heard a number, it seemed permanently photographed in his brain. In like manner he could study a complicated diagram without seeing it, when walking and apparently listening to a friend talking to him on some other subject. The diagram stood before him in all its lines and letters.

The second letter is from Mr. George Bidder, who writes:

His memory was of a peculiar cast, in which figures seemed to stereotype them. selves without an effort (accompanied) by an almost inconceivable rapidity of operation. I speak with some confidence on the former of these faculties, as I possess it to a considerable extent myself (though not to compare with my father). Professor Elliot says he always saw mental pictures of figures and geometrical diagrams. I always do. If I perform a sum mentally it always proceeds in a visible form in my mind; indeed, I can conceive no other way possible of doing mental arithmetic,

All this shows that mental impressions of extreme vivi the same time have great mobility and be subject to an a ceivable rapidity of operation, and that they need not be way that hallucinations often are.

Next as regards actual blending. Mr. G. Bidder, in ve plying to some questions that I put, writes:

Nothing is easier than to imagine, and to watch mentally, the rotat to which such motion is natural, e. g. a wheel, a crank, &c. In ma incline to think the process consists in calling up a sort of typical im of innumerable bygone experiences.

This was Mr. Bidder's own view, quite independent of an from myself, and is therefore all the more valuable.

The strongest proof that those who have vivid memor objects are also capable of blending them, is found in such men as Macaulay. I am assured on excellent auth visual memory of book, page, and line was of the clea character; it was described to me as having been 'spectra fect definition. Yet no one better than Macaulay had vivid generalisation, that is, of creating a single clear in multitude of allied facts. Many poets and painters h visualising faculty in an extraordinary degree, while it is of poets and painters generally that we find the artistic p of producing pictures that are not copies of any individu sent the characteristics of large classes. Painters and blended portraits in profusion, and we who are not gifte can nevertheless understand and appreciate their worl words, their blended images are well-defined representa we ourselves had already conceived in a dim and confuse

There seems then to be no doubt, from whatever s approach the subject of memory-whether from its m mental aspect, and, in the latter case, whether the visuali faint or vivid that different special memories admit wi being blended into a common image. From blended general impressions and ideas is a step on which we nee the latter being derived from the former. They are fa them, and they inherit all their errors.

I conclude, then, that the formation of blended images i operation of the mind, whence those general impression by which the great majority of our daily actions are guid

I will now proceed to speak of blended portraits, in o trate the formation of blended memories and the effect of