Page:Popular Science Monthly Volume 19.djvu/586

570 The more disagreeable symptoms had gone, but the mountaineers still found themselves "comparatively lifeless and feeble, with a strong disposition to sit down when we ought to have been moving." At length, having spent three days in moving their camp, and having passed a night at the highest station, they undertook the ascent to the summit. It was extremely difficult, made in the face of a high wind and through soft snow in which the men sunk to their necks, but it was accomplished, the measurement of the height was taken, and the return safely made to the camp, all in one day. The most notable physical experience of the ascent was the observation, at a height of between 18,400 and 19,500 feet, that "our steps got shorter and shorter, until at last the toe of one foot touched the heel of the previous one." Mr. Whymper's residence on Chimborazo "extended over seventeen days; one night was passed at a height of 13,400 feet, ten nights at a height of 16,500 feet, six at 17,300 feet. During this time, besides the ascent to the summit, I also went three times as high as 18,300 feet. When we quitted the mountain, all traces of mountain-sickness had disappeared, nor did it touch us again until we arrived at the summit of Cotopaxi." The camp on the latter mountain was placed about 130 feet below the loftiest point, or at a height of 19,4'70 feet, "and was the most elevated position at which any of us had ever lived. We remained there twenty-six consecutive hours, feeling slightly at first the effects of the low pressure, having the same symptoms as we noticed on Chimborazo; and we used chlorate of potash, and remarked its good effects. All the signs of mountain-sickness had passed away before we commenced the descent, and they did not recur again during the journey." The member of the party who suffered least from mountain-sickness was Mr. Perrin, the interpreter, who was in bad health from having led a dissipated life, and "could not walk a quarter of a mile on a flat road without desiring to sit down"; but he had lived for a long time at heights of between 9,000 and 10,000 feet, and had several times passed over a height of more than 14,000 feet; so that he was partly inured to the rarefied air. Chimborazo was visited again six months after the first visit, and a second measurement of the height was made. The mean of the two measurements gives 20,517 feet.

Structure of the Organs of Touch.—M. Ranvier has been much assisted in his investigation of the structure of the organs of touch by the examinations of the structure of infants. At birth, the nerves of touch may be found to pass into certain papillæ, on the palmar aspect of the fingers, immediately beneath the cells of the mucous layer of Malpighi, where they form a network of ramifications which, though distinct, are closely pressed together. No cellular elements are at this time mixed with the network, but a small collection of round cells exists beneath it. These gradually surround the network and pass in among its branches; the whole soon becomes united, and a tactile corpuscle is formed. Sometimes the corpuscle remains unilobar, but more frequently other lobes are formed in the same manner as the first one, and are joined to it. Hence it is that, in young children, the nerve-fibers which enter into the composition of the tactile corpuscles are separated by layers of cells, which, in the course of development, become pushed to the periphery of each lobe, and the most of them undergo a considerable atrophy. This fact suggests that they are not nervous in their nature, for the nerve-cells, so far from undergoing atrophy during growth, gradually increase in size to their full development. M. Ranvier has not perceived any communication between the nerve-fibers and the cells in the tactile corpuscle; the ramifying branches of the nerve-fibers, after a tortuous and usually complicated course, end in free, flattened knobs.

Influence of Physical Structure on Processes of Dyeing.—M. Gustave Engel has been engaged for several years in studying the influence which the physical structure of substances exercises upon the operations of dyeing, and has remarked that certain sands, composed of silica, a substance chemically inert, behave, in the presence of different coloring-matters and dyes, exactly in the same manner as cotton and wool. On examining with a microscope siliceous sands