TEMPERATURE OF THE HYDROSPHERE 203 



sphere, in the form of emanations. Tschermak, Reyer, de Lap- 

 parent, Kemp and others have actively supported the view of the 

 importance of such magmatic waters, especially as causes in ore 

 deposition, a view advocated by Elie de Beaumont before 1850. 

 (Kemp-19: (5/o-(5/5; 'Linco\n-2i : 2j8-2/'4.) Armand Gautier (9) 

 has shown that when powdered igneous rocks (granites, porphyries, 

 trachytes, gneisses, gabbros, etc.) are raised to a red heat in a 

 vacuum they give off water and gases among which hydrogen and 

 carbon dioxide predominate. This is not water taken in by the 

 rock, but water of constitution. The quantity of water lost at red 

 heat varies from 7 grams per kilogram in granite to nearly 17 

 grams per kilogram in Iherzolite. With the water is driven off 

 from 3 to 18 times its volume of gases which are only in small part 

 included gases, being produced mainly by the action of the ferrous 

 salts in the rock upon vapor of water at a red heat. These gases 

 are similar to volcanic gases, being rich in free hydrogen and COo. 

 The great eruption of Etna -in 1865 supplied 11,000 metric tons of 

 water a day for 200 days, or a total of over 2,000,000 tons for this 

 critical period. A cubic kilometer of granite would furnish at red 

 heat, from 25 to 30 million tons of water, one-fourth of which would 

 be sufificient to supply a volume like that given out by Etna during 

 the whole eruption of 1865. "De Laumy estimates that the princi- 

 pal thermal springs of France discharge a total of 700,000 hecto- 

 liters of water in 24 hours. The water which issues from a single 

 cubic kilometer of granite raised to a temperature of 600° or 700° 

 C. would suffice to keep all these springs running for a year with a 

 flow of 48,500 liters a minute." (Gautier-9 : dpi".) Suess regards 

 the springs of Carlsbad, Bohemia, as having their source in mag- 

 matic emanations, and he also places the hot waters of Iceland and 

 the Yellowstone under this category. In fact, if we accept the con- 

 clusions of Kemp and others that the meteoric water is limited to 

 the upper 2,000 feet or less of the earth's crust, we are forced to 

 regard most thermal springs as newly originated or magmatic waters 

 emanating from a not too deeply buried igneous mass which has not 

 yet wholly expired. "Thermal springs," says Armand Gautier, 

 "may be explained as a kind of gentle distillation of crystalline 

 rocks in a region so hot that water of constitution tends to escape 

 upon a slight increase in temperature." (9'-693-) The view is 

 also held to some extent by geologists that mineral veins owe their 

 origin to just such emanations, the magmatic waters carrying with 

 them in solution the mineral matter to be deposited in the fissures 

 penetrated by these waters. (See Kemp-19 for summary of most 

 recent opinions; also Schneider-35 and Hague-ii.) 



