is absent, the table where it is present, the table where the effect is shown in various degrees, so as to isolate and bring to light the condition which produced it.[390] Then we shall have, not useless universal axioms, but efficacious mediate axioms, true laws from which we can derive works, and which are the sources of power in the same degree as the sources of light.[391] Bacon described and predicted in this modern science and industry, their correspondence, method, resources, principle; and after more than two centuries it is still to him that we go even at the present day to look for the theory of what we are attempting and doing. [Illustration: CHOICE EXAMPLES OF EARLY PRINTING AND ENGRAVING. Fac-similes from Rare and Curious Books. _THE NEW PSALTER OF THE VIRGIN MARY._ The "Novum Beatæ Mariæ Virginis Psalterium" was printed by the Cistercians monks of the monastery of Sienna, in the duchy of Magdeburg, near Wittemberg, in 1492. The present illustration shows the page of dedication, in which mention is made of the Emperor Frederick, whose arms, the double-headed eagle, appears in the border. The book was printed in the year before the emperor died. The border is an easy and flowing design of roses, which are always considered an emblem of the Virgin. The volume is a remarkable production, rare and much prized by collectors.] Beyond this great view, he has discovered nothing. Cowley, one of his admirers, rightly said that, like Moses on Mount Pisgah, he was the first to announce the promised land; but he might have added quite as justly, that, like Moses, he did not enter there. He pointed out the route, but did not travel it; he taught men how to discover natural laws, but discovered none. His definition of heat is extremely imperfect. His "Natural History" is full of fanciful explanations.[392] Like the poets, he peoples nature with instincts and desires; attributes to bodies an actual voracity, to the atmosphere a thirst for light, sounds, odors, vapors which it drinks in; to metals a sort of haste to be incorporated with acids. He explains the duration of the bubbles of air which float on the surface of liquids, by supposing that air has a very small or no appetite for height. He sees in every quality, weight, ductility, hardness, a distinct essence which has its special cause; so that when a man knows the cause of every quality of gold, he will be able to put all these causes together, and make gold. In the main, with the alchemists, Paracelsus and Gilbert, Kepler himself, with all the men of his time, men of imagination, nourished on Aristotle, he represents nature as a compound of secret and living energies, inexplicable and primordial forces, distinct and indecomposable essences, adapted each by the will of the Creator to produce a distinct effect. He almost saw souls endowed with latent repugnances and occult inclinations, which aspire to or resist certain directions, certain mixtures, and certain localities.