Page:Popular Science Monthly Volume 10.djvu/137

Rh by the revolutions of the nearest axle under the car. A lead-pencil placed about the centre of the paper indicates by its mark the condition of the track. The more uneven the track the longer will be the mark made by the pencil. Another way of showing the inspecting party that the track is uneven is by an horizontal piece of iron or steel, which oscillates like the pendulum of a clock as the train moves. When a very defective point is reached, the pendulum comes in contact with a metal on each side, circular in shape, which gives a sound like a bell.

Physiological Action of Coca.—The physiological action of the leaves of coca or cuca (Erythroxylon coca), a plant indigenous to Peru, has been the subject of much discussion lately in England. Sir Robert Christison, whose reference to the peculiar properties of this plant, in his address to the Edinburgh Botanical Society last November, gave rise to the discussion, has since taken up the subject again, in a paper read before the same society. The author gives an account of experiments made by himself and by fourteen other observers, under his instructions, with a view to determine the physiological action of coca and its principle, cocaine. His conclusions are that—1. When taken in quantities of two drachms by healthy persons it has no unpleasant, injurious, or suspicious effect whatever; 2. In a very few cases this dose of an inferior sample had no effect at all; 3. In by far the greater number of instances, and with a fine sample, extreme fatigue was removed and prevented from returning; 4. It does not in the end impair the appetite or digestion, although hunger, even after long fasting, is taken away for an hour or two; 5. The use of it is incompatible with the use of alcoholic liquors, except when the latter are taken in very small quantities.



a recent Miscellany article on the cruise of the Challenger, it was stated that 4,975 fathoms, or five and a half miles, is the deepest trustworthy sounding yet made, excepting two by the Tuscarora, which showed a depth 600 feet greater. A correspondent has called our attention to a statement in No. IV. of the "Science Primer Series," to the effect that between the Azores and Bermudas a sounding had been obtained of seven and a half miles. This sounding was made twenty years ago, by Lieutenant Berryman. It was in latitude 32° 55' north, and longitude 47° 58' west, but it is not now regarded as trustworthy. A fruitful source of error, in this and other early soundings, was the curving of the line by currents, etc.

of Chicago, has been appointed director of the Dearborn Observatory in that city. Mr. Burnham's contributions to observational astronomy, mostly published in the "Transactions" of the Royal Astronomical Society of London, have earned for him prominent rank among astronomers, both at home and abroad.

a recent Italian work, measurements are given of the skulls of Dante, Petrarch, Ugo Foscolo, and Volta. Volta's skull is of extraordinary capacity. In the skull of Petrarch the Etruscan type is evident, viz., a voluminous brain, strongly developed in all its parts, and of superior psychological power; but the posterior predominates over the anterior portion, leading to the conclusion that the sentiments and instincts prevailed over the intellect.

is asserted, by Prof. Isidor Walz, that vanadium is a general constituent of American magnetites. This conclusion is based upon examination of twenty-seven specimens of magnetites from different localities, in the United States and Canada.

Austria, according to the Moniteur Industriel Beige, dynamite has been employed with success in vine-culture. In order to loosen the soil and permit access of air and moisture to the vines, cartridges of dynamite were placed in holes three metres deep, at such distances from the plants as to obviate the danger of injury to them from an explosion. The result of the explosion was that the soil was perfectly broken up to the depth of two and a half metres. Furthermore, the phylloxera completely disappeared. Certainly a novel use for explosive agents.

June 27th, at the age of eighty-two, Christian Gottlieb Ehrenberg, the eminent microscopist. In 1820 he was attached to a scientific expedition into Egypt, and for six years devoted himself to the microscopic investigation of the lower animal forms of that and the neighboring countries. On his return home he was appointed a professor in the medical faculty of the Berlin University. In 1829 he accompanied Humboldt to Central Asia. He was the author of numerous works upon microscopic organisms.