_Is there an Open Arctic Sea?_--Sir Roderick Murchison, who answers this question in the affirmative, gives the following arguments in support of his opinion:--(1.) The fact has been well ascertained by Scoresby and others, that every portion of the floating pack-ice north of Spitzbergen is made up of frozen sea-water only, without a trace of terrestrial icebergs like those which float down Baffin's Bay, or those which, carrying blocks of stone and _débris_, float northward from the land around the South Pole. (2.) The northern shores of Siberia tell the same tale; for in their vast expanse the absence of icebergs, or erratic blocks, or anything which could have been derived from great or lofty masses of land, has been wen ascertained. (3.) As a geologist, Sir R. Murchison could point out that this absence of erratic blocks in northern Siberia has existed from that remote glacial period when much larger tracts of northern Europe were occupied by glaciers than at the present day. (4.) The traveller Middendorf found the extreme northern promontory of Siberia, Taimyr, clad with fir trees, while the immense tract of country to the south of it was destitute of trees, showing a milder climate at that point of Siberia nearest the pole. _Food as a Means of Preventing Disease_,--It seems not at all improbable that, as has been shown by Liebig in the case of plants, most of those diseases which we at present attribute to the presence of some morbid substance in the blood, are produced in the first instance by the absence of some of the proper constituents of the blood. The blood when abnormally composed will allow vegetable and other growths to take place in it, thus producing painful symptoms; but if it contained its suitable components, it is most probable that it would be then enabled to resist the development of the materials we refer to. In the case of the potato disease, there can hardly be a doubt that the sap becomes deteriorated, owing to the absence of the proper proportion of potash, prior to the development of the oïdium which commits such ravages. The idea which we have given has not had many advocates in this country, and we are glad to find that Mr. Erasmus Wilson has in some measure lent his support to the theory. Although Mr. Wilson does not go as deeply into the question as we should wish, still he shows that food may well be employed not only in preventing but in curing disease. If, he says, it be admitted that food is the source of the elements of which the body is composed, what kind of body can be expected in the case of a deficient supply of food, whether that deficiency proceed from actual want, or from some perverse theory of refinement, founded on a false conception of the nature and objects of food, and ignorance of its direct convertibility into the flesh and blood of man? We think Mr. Wilson is too determined a supporter of flesh-eating tastes. If he had his way, he would