In the reign of Augustus, when Rome had about 350,000 inhabitants within its walls, there was a supply of something like 680 gallons per head; that is, about forty times as much as the valuation for Vienna. But there were in ancient Rome no less than 1,352 public fountains, 591 jet fountains, 19 large fortified camps or barracks, 95 thermæ or immense public baths, and 39 arenas or theatres, all of which were supplied with a superfluity of constantly flowing water. The reservoirs contained only about 6,000,000 gallons, and the distribution must have been very irregular, and it has been calculated that some houses received ten times as much water as others. Just as the Western miner reckons the quantity of water by the inch, the Roman estimated it by the quinarius, or amount that could flow through a pipe of one and a quarter finger diameter, under a head of twelve inches. This would yield about ninety-two gallons in twelve hours, and the price was so low that the householder paid only about half a cent per year for each gallon supplied daily. Ninety-two gallons a day would therefore cost less than half a dollar a year. (In New York it would cost nearly $18.) But though cheap, the water was not a vested right of all citizens. The poor had it for nothing in the ample baths, wash houses, and fountains, but householders could only obtain the right of water supply by a petition to the consul, and in later times to the emperor himself; even then, however, with difficulty. It was a matter of favor and a reward of merit, that applied only to the person to whom it was granted, not transferable by gift or sale, and which lapsed with the death of the owner or the sale of the house for which it had been granted.
GALVANISM CANNOT RESTORE EXHAUSTED VITALITY.
Dr. B. W. Richardson says that artificial respiration is a much more effective means of restoring the drowned or asphyxiated than galvanism. By the use of an intermittent current of galvanism it is possible to make the respiratory muscles of an animal recently dead act in precise imitation of life, and the heart can be excited into brisk contraction by the same means. But the result was that "the muscles excited by the current dropped quickly into irrevocable death through becoming exhausted under the stimulus, and that in fact the galvanic battery, according to our present knowledge of its use in these cases, is an all but certain instrument of death. By subjecting animals to death from the vapor of chloroform in the same atmosphere, and treating one set by artificial respiration with the double-acting pump, and the other set by artificial respiration excited by galvanism, I found that the first would recover in the proportion of five out of six, the second in proportion of one out of six. Further, I found that if during the performance of mechanical artificial respiration the heart were excited by galvanism, death is all but invariable." This results from the fact that "the passage of a galvanic current through the muscles of a body recently dead confers on those muscles no new energy; that the current in its passage only excites temporary contraction; that the force of contraction resident in the muscles themselves is but educed by the excitation, and to strike the life out of the muscles by the galvanic shock without feeding the force, expended by contraction, from the centre of the body, is a fatal principle of practice."
CURIOUS OPTICAL EXPERIMENTS.
Prof. Nipher of the Washington university at St. Louis describes some optical illusions, easily tried and apparently very singular, as follows: 1. Fold a sheet of writing paper into a tube whose diameter is about three cm. Keeping both eyes open, look through the tube with one eye, and look at the hand with the other, the hand being placed close by the tube. An extraordinary phenomenon will be observed. A hole the size of the tube will appear cut through the hand, through which objects are distinctly visible. That part of the tube between the eye and the hand will appear transparent, as though the hand was seen through it. This experiment is not new, but I have never seen it described. The explanation of it is quite evident.
2. Drop a blot of ink upon the palm of the hand, at the point where the hole appears to be, and again observe as before. Unless the attention be strongly concentrated upon objects seen through the tubes the ink-spot will be visible within the tube (apparently), but that part of the hand upon which it rests will be invisible, unless special attention be directed to the hand. Ordinarily the spot will appear opaque. By directing the tube upon brilliantly illuminated objects, it will, however, appear transparent, and may be made to disappear by proper effort. By concentrating the attention upon the hand, it may also be seen within the tube (especially if strongly illuminated), that part immediately surrounding the ink spot appearing first.
3. Substitute for the hand a sheet of unruled paper, and for the ink spot a small hole cut through the paper. The small hole will appear within the tube, distinguishing itself by its higher illumination, the paper immediately surrounding it being invisible. Many other curious experiments will suggest themselves. For example: if an ink spot somewhat larger than the tube be observed, the lower end of the tube will appear to be blackened on the inside.