Page:Popular Science Monthly Volume 27.djvu/735

Rh branch gallery was broken and drawn several yards into the main gallery, but the outer one remained intact. The incidental effects of the last two shots also indicated how tremendous a force had been let loose when coal-dust formed one of the elements of the explosion. These experiments were typical of two hundred similar ones that had been made with from one to seven guns, all marked by results sustaining the coal dust theory.

Medical Virtues of Dog's Tongues.—M. Reimach having called attention to the mention, in the recently discovered inscriptions at the Temple of Esculapius, in Epidaurus, of children having been cured of blindness at that sanctuary by having their eyes licked by the sacred dogs, M. Henri Gaïdoz states that he has discovered the faith and practices of the dog-cure among several peoples and in a number of religions. The Hindoos believe that the English kill dogs to obtain possession of a sovereign remedy which is found in their tongues. In a Venetian legend, St. Roch was cured by a balsam distilled from the tongue of his dog. Dogs' tongues are considered to have medical virtue by many people in Portugal, France, and Scotland. In Bohemia they let dogs lick the faces of new-born children for "good luck." A belief in the existence of divinities issuing from dogs, whose office it was to lick the bruises of the wounded, once prevailed in Armenia. In a scene in one of Aristophanes's plays, Plutus recovers his sight in the Temple of Esculapius after being licked by two serpents which the god sent for that purpose in answer to his prayer.

Observations in the Sahara.—Dr. Oscar Lenz, whose account of his journey through Morocco, the Sahara, and the Soudan, to Timbuctoo, has been recently published, is the fourth European traveler who has reached the famous "Queen of the Wilderness," as the desert metropolis is called, during the present century. Having entered the city from the north, and then going from it westward and down the Senegal to the Atlantic coast at St. Louis, he has demonstrated the accessibility of Timbuctoo from both directions. One of the results of the surveys he made on his journey will probably be the death of the theory that the region of the Sahara has ever been a marine basin, at least since the early Tertiary epoch. The whole of the western section of the desert traversed by him was proved not to be a depression, as has been assumed, but an irregular plateau; standing in the north at a mean elevation of from eight hundred to one thousand feet, and even at Tandeni, its lowest level, still maintaining an altitude of four or five hundred feet above the Atlantic. The surface formations have nothing in common with marine sedimentary deposits, but are all evidently the results of weathering. The numerous dried-up water-courses, whose deep channels are distinctly the effect of erosion, also show that this part of the desert has been dry land for many ages. These wadies radiate from the central highland north and northeast to the Mediterranean, east to the Nile, south to Lake Chad and the Niger, and west to the Atlantic, and have been in their day full of water. Hence, it appears that, down to comparatively recent times, the Sahara was a well watered and wooded region, thickly inhabited by agricultural and pastoral communities. What has caused this change in climate? Dr. Lenz attributes it, not as Peschel has supposed, to the dry northeast polar winds (for these in the Sahara yield to the northern and northwestern atmospheric currents), but largely to the reckless destruction of the woodlands which once covered extensive tracts in the region.

Value of Fruit as Food.—The "Lancet" regards the increased use of fruit in ordinary diet as one of the most salutary tendencies of domestic management in our day. The starchy and saccharine components of fruit, while they are not equal in accumulated force to the more solid ingredients of meat and fat, are similarly useful in their own degree, and have the advantage of greater digestibility. Other advantages are the locally stimulant action of many sub-acid fruits, its control of a too active peptic secretion, and its influence of attraction upon the alkaline and aperient intestinal juice, to which further effects that aid the maintenance of a pure and vigorous circulation are indirectly due. "Thus it follows,