GEOPHYSICAL LABORATORY. 



145 



The detailed results of the experiments are summarized in tables and also 

 presented graphically by means of curves and photographs of solid models. 

 The curves show the solubility relations in the binary systems H20-K2Si03 

 and H20-K2Si205, the isothermal polybaric saturation curves and the variation 

 of vapor pressure of the solutions on each isotherm with the Si02/K20 ratio in 

 the solution, the isobaric poly thermal saturation curves, and the P-T curves 

 of the various monovariant systems, i. e., systems containing four phases, in 

 the ternary system. The solid models show the variation of the composition 

 of the saturated solutions with temperature under the corresponding 3-phase 

 pressures, and the variation of the composition of the saturated solutions 

 with pressure at the corresponding 3-phase temperatures. 



A short discussion of some of the theoretical considerations which govern 

 the equilibrium relations in binary and ternary systems containing a volatile 

 component is given and the proper use of the term "solubility" is discussed. 



(13) Persistence of vents at Stromboli and its bearing on volcanic mechanism. Henry 



S. Washington. BuU. Geol. Soc. Amer., 28, 249-278 (1917). 



In August 1914 six vents were active on the crater terrace of Stromboli. 

 Examination of plans and illustrations in the literature (many of which are 

 reproduced in the paper) shows that at least three of these vents have per- 

 sisted in location as far back as 1768. Similarly, at Kilauea the main vent has 

 persisted in location for about a century ; and there is evidence of such persist- 

 ence at some other volcanoes. This feature of volcanoes seems to have been 

 previously unnoticed. Another notable feature of the Stromboli vents is that 

 the three oldest of them open about 1,000 meters above sea-level near the 

 upper edge of a precipitous scarp of that height. An analogous situation is 

 true of some of the vents at Etna and also of one or two of those of Kilauea. 



In the discussion of these and other features it is shown that such vents 

 can not have originated through explosive agencies; but that their formation, 

 situation, persistence in location, and other features, can best be explained 

 by Daly's so-called "gas-fluxing hj'^pothesis," which supposes a "blow-piping" 

 of narrow, vertical vents through the superjacent rocks by gases derived from 

 the magma in its reservoir below and which are heated and kept hot by 

 chemical interreactions. 



(14) The equiUbrium between carbon monoxide, carbon dioxide, sulfur dioxide and free 



sulfur. John B. Ferguson. Proc. Nat. Acad. Sci., 3, 371-374 (1917). 



In this paper is presented a preliminary summary of the 

 results of an extended research on the equilibrium between car- 

 bon monoxide, carbon dioxide, sulphur dioxide, and free sul- 

 phur at high temperatures. These gases react according to 

 the equation CO+|S02<ii2lC02+iS2, and this reaction is one 

 of the chief gas reactions involved in volcanic activity. It 

 has great importance also from the fact that from a study of 

 it the free energy' of sulphur dioxide, a quantity indispensable 

 to a proper study of the chemistry of the sulphur compounds, 

 may be obtained directly. 



The character of the results presented may best be shown 

 by the accompanying table, which gives the various values 

 for the thermodynamic constant I derivable from the equi- 

 librium constants obtained. 



From the above data the free energy changes under standard conditions 

 (AF298) have been calculated and are given below: 

 GO-}-|S02 = C02+iS2 AF298= -22529 Sr+02 = S02 aF29s= -69757 



