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THE POPULAR SCIENCE MONTHLY, 



and the general sanitary administration 

 take its place in England. The sanitary 

 administration is so devised that every dis- 

 trict, whether inland or on the coast, is 

 enabled to deal with infectious disease, com- 

 ing from whatever source, in the most effi- 

 cacious 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 l)e deemed necessary. Ex- 

 perience 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 disturb- 

 ances to commerce which have arisen and 

 must arise from quarantine." 



Retreat of Glaelcrs. M. Charles Dufour 

 read a paper on the retreat of glaciers, at 

 the recent meeting of the French Associa- 

 tion for the Advancement of Science. His 

 observations of the phenomena were begun 

 in 18Y0, while he was sojourning by the 

 glacier of the Rhone 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 inhabi- 

 tants 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 Rhone. 

 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. Informa- 

 tion is still wanting with reference to the 

 glaciers of the Scandinavian Alps. A gen- 

 eral retreat of so much importance as ap- 

 pears to be shown can hardly be explained by 

 a theory of casual modifications of climate. 



American Storms in Europe. M. IIc- 

 bert communicated to the French Associa- 

 tion 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 Colom- 

 bia and Venezuela. Ue traced the forma- 

 tion, 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. 

 lie 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, Cen- 

 I tral America, and the northern parts of 

 South America ; but they do not generally 

 strike the Atlantic till after they have trav- 

 ersed 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 neigh- 

 borhood of Iceland or the Faroe Islands, too 

 far away to affect Europe. 



Carbonic icid in the Sea. In com- 

 municating his studies on the proportion 

 of carbonic acid in the air, M. Schloesing 

 remarks that some of the causes which reg- 

 ulate the production and consumption of 

 this substance are subject to considerable 

 and relatively rapid variations ; such are 

 vegetation and the slow combustion of or- 

 ganic 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 cir- 

 culation and the commingling operation of 

 tlae 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 



