Theoretical crystallography, approached by Stenc (1669), but formally founded by Hatty (1781, Trait, 1801), has limited its development during the century to systematic classifications of form. Thus the thirty two type sets of Hessel (1830) and of Bravais (1850) have expanded into the more extensive point series in volving 230 types due to Jordan (1868), Sohncke (1876), Federow (1890), and Schoenfliess (1891) Physical theories of crystalline form have scarcely been unfolded. The evolutionist is spared the surpassing difficulty ol the human element, yet he needs imagination. In its lowest form his imagination is that of the detective who reconstructs the story of a crime; in its highest it demands the power of breaking loose from all the trammels of convention and education, and of imagin ing something which has never occurred to the mind of man before. In every case the evolutionist mus1 form a theory for the fads before him, and the greal theorist is only to be distinguished from the fantastic -fool by the sobriety of his judgment--a distinction however, sufficient to make one rare and other only too common. The science of architecture, if under this head we include the principles of building construction, and the heating and ventilation of buildings, has done and is doing much of interest and importance to the student of public health science. The air supply, especially for the modern civilized and too often sedentary form of mankind, is in the long run quite as important as the water supply, the milk supply, or any other supply. Surely, we can not he too careful of the purity of a substance which we take into our bodies oftener, and in larger volume, than any other, and which has come, rightly no doubt, and as the result of long and painful experience, to be known as the very breath of life. Human beings may survive and seemingly thrive, even for long periods, in bad air, but for the best work, the highest.efficiency, the greatest happiness and the largest life, as well as for perfect health, the very best atmosphere is none too good. Hence the Permeability of the wallsof houses and other buildings, and the heating and ventilation of dwellings, school houses, churches, halls and other public places, require, and in the near future will receive, a much larger share of our attention than they have to-day. Aside from their economic value, grape vines are often cultivated for purely ornamental purposes, owing to their beautiful foliage and the rich coloration they assume, the shade they afford, and their hardihood and longevity. The vine is one of the few plants that can be conveniently grown in cities or towns either as bushes or for making delightful arbors that not only beautify the home, but furnish cooling shade and luscious fruit. The more tender sorts can be grown in graperies in many regions with good profit, and when grown in pots not only serve as handsome decorations in the dwelling and on the table, but add one of the choicest of morsels to the menu as well. To quote the language of an enthusiast: The grape is the poor mans fruit, especially one who has only a house lot of the smallest possible dimensions. He can plant vines beside his cottage and their roots will extend and profitably occupy every inch of ground underneath it, and from that small space produce all the fruit his family can consume, while the vines afford shade and protection and add beauty to his little home, occupying no space, either above or below the ground, to interfere with other interests, and producing more fruit in less time- and with less labor and attention than any other thing that was ever planted. Information is being sought by people all over the country on the subject of testing of clays for the various purposes for which they are used, other than road building.. Special tests are now carried on to that end. A furnace has been installed by the Department of Agriculture and actual burning tests on clays are now made. In order to further stimulate interest in the development of native clay bodies, a special circular was issued on The Useful Properties of Clays. The aim of this circular was to give information in the simplest possible way to people who were not supposed to possess technical knowledge of clays. The circular particularly points out that for the year 1902, the last year for which the official figures are valuable, the total imports of foreign clays to this country were valued at. 1,154,805, while the domestic clays produced were valued at 2,061,072. Since the country possesses unusually fine clay bodies, a great many of which up to the present time await development, any stimulation of interest among the people to develop our native clays must be of great value.