Page:Popular Science Monthly Volume 38.djvu/299

Rh the time of Aristotle. It consisted of two exactly similar earthen vessels filled with water, each provided with a cock that would discharge an equal quantity of water in a given time, so that the whole or any part of the contents would escape in precisely the same period from both vessels. On the surface of each floated a piece of cork supporting an upright, marked off into divisions, each division having a certain sentence inscribed upon it. One of the vessels was placed at each station, and when either party desired to communicate with the other he lighted a torch which he held aloft until the other did the same, as a sign that he was all attention. On the sender of the message lowering or extinguishing the torch, each party immediately opened the cock of his vessel, and so left it until the sender re-lighted his torch, when it was at once closed. The receiver then read the sentence on the division of the upright that was level with the mouth of the vessel, and which, if everything had been executed with exactness, corresponded with that of the sender, and so conveyed the desired message.



presented, in the American Association, the evidence in support of his belief that there was, in the Wabash River, one last great flood near the close of glacial time, and that then the water-supply was so cut off or diminished that there was never another freshet large enough to wipe out or modify the marks it left. This flood, in the opinion of the author, carried about one hundred times as much water as do the great floods of the present time.

largest barometer yet made has been put in working order in the Saint Jacques Tower, in Paris. It is forty-one feet five inches high.

International Medical Congress met in Berlin, August 4th. Members of the medical profession were present representing every state and city in Europe, and many from North and South America. An opening address of welcome was made by the president, Prof. Virchow. Welcoming addresses were also given for Prussia and Berlin. Dr. Lassar, Secretary-General of the Congress, sketched the general plan of the labors of the Congress, and gave some statistics concerning the representation of the countries taking part in it. Dr. Hamilton, Surgeon-General of the United States Army, was the first regular speaker, and was followed by Sir James Paget and Sir Joseph Lister.

corrosion of steel by salt water is said to be much greater than that of iron. Mr. David Phillips stated, iii a recent address before the British Institute of Marine Engineers, that he had experimented from 1881 to 1888 with two plates of Bessemer boiler steel, two of Yorkshire, and two of B. B. Staffordshire boiler iron. The plates were as nearly as possible six by six by three eighths inches, and were kept immersed in salt water. The results show a great difference between the behavior of steel and iron. The steels lost 120 per cent more than the irons the first three years, when the plates were in contact; 124 per cent more the second three years, when they were insulated; and 126 per cent more for the whole period of seven years.

some of our investigators of bacteria are mistaken, there seems to be hardly a situation where these minute organisms may not be found. Thus Dr. Charles M. Cresson claims to have discovered typhoid bacilli in the juice squeezed from some celery grown near Philadelphia; and the Johns Hopkins Hospital Bulletin for May, 1890, records some observations, by A. C. Abbott, upon bacteria found in the interior of large hailstones which fell during the storm of April 26, 1890.

Australasian Association for the Advancement of Science will hold its third annual meeting at Christchurch, New Zealand, beginning January 15,1891. Sir James Hector, F. R. S., will succeed Baron F. von Müller, F. R. S., as president, and will deliver an address. Arrangements are making to secure reduced excursion fares from the other Australian colonies, and probably from Great Britain.

his lecture on caves, at the meeting of the American Association, the Rev. Dr. Hovey exhibited a photograph made by L. Farini, of Bridgeport, Conn., from an ordinary negative, by means of the light of the fire-fly (Elator phocans).

object of certain experiments described by Mr. W. Sharp, in the British Association, was to answer the question, What is the action of the substances called drugs upon the living body of man? The conclusions arrived at were the results of experiments made upon men in sound health, with different quantities of the same drugs. In the case of fourteen drugs that were used it was found that the smallest doses administered have power to act upon the living human body; that the commonly received opinion that the actions of drugs are simply increased in degree, and not altered in character, by increasing the dose, is an error; and that the actions of drugs are sufficiently distinct to admit of classification. 