Open main menu

Page:Popular Science Monthly Volume 18.djvu/882

This page has been validated.
862
THE POPULAR SCIENCE MONTHLY.

and the general sanitary administration take its place in England. The sanitary administration is so devised that every district, whether inland or on the coast, is enabled to deal with infectious disease, coming from whatever source, in the most efficacious manner. The sanitary authorities of the ports are, moreover, given power to inspect medically persons arriving in ships from infected places, remove and isolate the sick, and use whatever processes of disinfection may be deemed necessary. Experience has shown that this system "does all that the most efficient quarantine can be hoped to do, and that more effectually, without involving those grave hardships to individuals and interruptions and disturbances to commerce which have arisen and must arise from quarantine."

 

Retreat of Glaciers.—M. Charles Dufour read a paper on the retreat of glaciers, at the recent meeting of the French Association for the Advancement of Science. His observations of the phenomena were begun in 1870, while he was sojourning by the glacier of the Rhône for the purpose of measuring the amount of the condensation of vapor on the ice. In connection with Professor Forel, he made a chart of the front of the glacier, as it was defined by reference to marks fixed in the moraine. The comparisons for the revision of the chart from year to year established the fact that the glacier was constantly receding. According to the statements of the inhabitants of the country, the retreat began in 1855 or 1856, and it now exceeds all that has been otherwise certainly determined within historical times. This phenomenon is not peculiar to the glacier of the Rhône. All of the glaciers of the Alps have begun to recede at some time more or less distant, and some of them have even disappeared. The same is the case with the glaciers of the Pyrenees and the Caucasus. Information is still wanting with reference to the glaciers of the Scandinavian Alps. A general retreat of so much importance as appears to be shown can hardly be explained by a theory of casual modifications of climate.

 

American Storms in Europe.—M. Hébert communicated to the French Association for the Advancement of Science the results of an investigation which he had made, day by day, during six months of winter, of the meteorological phenomena of North America from Greenland to Colombia and Venezuela. He traced the formation, along the grand mountainous crest of the continent and on its eastern slope, of powerful phenomena of sirocco, which dried the continent and limited its vegetation. He followed the rotatory storms which are produced on these crests step by step across the continent and the adjacent seas and to the western coasts of Europe. These storms, which are much more powerful than those which he has investigated in Europe, have otherwise, but with much more intensity, the same characters with them, and are the source of the depressions and tempests which are experienced in Europe. The storms which reach the European coast originate for the most part in Mexico, Central America, and the northern parts of South America; but they do not generally strike the Atlantic till after they have traversed a more or less extended part of the length of the North American Continent. The storms which originate in the United States reach Greenland, or pass the neighborhood of Iceland or the Faroe Islands, too far away to affect Europe.

 

Carbonic Acid in the Sea.—In communicating his studies on the proportion of carbonic acid in the air, M. Schloesing remarks that some of the causes which regulate the production and consumption of this substance are subject to considerable and relatively rapid variations; such are vegetation and the slow combustion of organic residua, the activity of which depends on the temperature. But, besides the fact that these variations take place in an inverse degree in the different regions of the globe, and therefore partly balance one another, there exists a powerful regulator of them, which combines its action with that of the circulation and the commingling operation of the atmosphere: it is the sea. Acting upon this idea, M. Schloesing has calculated the quantity of carbonic acid concealed in the seas, and has arrived at the conclusion that the sea holds in reserve a quantity of acid available for exchange with the atmosphere ten times greater than the whole quantity