GEOPHYSICAL LABORATORY. 145 



of stability of these compounds. The present paper treats of the mode of 

 experiment, the general behavior of the above two systems, and the prepara- 

 tion of four new crystalline sihcates; namely, KgO . HgO , Si02, K20.2Si02, 

 Na20.2Si02, and Na20.Si02, the general properties of which are described. 

 The second of these is identical with the product obtained by Niggli from 

 (dry) melts of potassium carbonate and silica (abstract No. 27) ; the fourth 

 is identical with the product obtained by Niggli from melts of sodium 

 carbonate and silica. It may be mentioned that the potassium silicate, 

 which when dry melts at about 1015°, yields in presence of water in a closed 

 vessel, at temperatures about 400°, perfectly fluid solutions containing from 

 8 to 30 per cent of water; this indicates that the melting-point of a (non- 

 volatile) silicate may be lowered enormously in presence of a relatively small 

 proportion of a volatile component such as water. 



(38) Neue kristallinische Kalium und Natrium Silikaten; Ihre Herstellung und Allge- 



meine Eigenschaften. George W. Morey. Z. anorg. Chem. (In press.) 



A German translation of "New crystalline silicates of potassium and 

 sodium; their preparation and general properties" (J, Am. Chem. Soc, 

 1913). Reviewed under No. 37 above. 



(39) Observations on the Daubree experiment and capillarity in relation to certain geo- 



logical speculations. John Johnston and L. H. Adams. J. Geol. (In press.) 



Those who believe that meteoric waters are an important factor in the 

 production of the phenomena of vulcanism must always face the problem of 

 devising a plausible account of the manner in which accessions of water can 

 be introduced into the magma. This difficulty they have endeavored to 

 obviate by instancing an experiment of Daubree, who found that water 

 would pass through a porous sandstone against a certain excess counter- 

 pressure of steam. This passage of water is, as Daubree pointed out, a 

 manifestation of capillary action; the authors show that this same effect 

 may be secured by means of a much simpler experimental arrangement. 

 Now capillary forces are effective only when there is a surface of separation 

 within the pores; moreover, they diminish steadily with rise of temperature, 

 and vanish at the critical point of the liquid. Consequently, the Daubree 

 experiment gives no ground for supposing that capillary forces would be 

 effective in causing water to penetrate into deep-seated and highly heated 

 rock-masses. This conclusion has been pointed out before; the purpose of 

 the present paper is to enforce it, since the opposite, and erroneous, con- 

 clusion still frequently appears as an argument in favor of the likelihood of 

 the introduction of water by means of capillarity into molten magmas. 

 Even if we make the somewhat unlikely assumption of free-liquid surfaces 

 far down in the rocks, any pressure producible by capillarity is in general 

 likely to be small in comparison with the pressure due to the hydrostatic 

 column, except in pores of such fineness that the amount of water that could 

 flow through them is infinitesimal. 



(40) liber den Daubrce'schen Versuch und Kapillaritat in Bezug auf gewisse geologische 



Spekulationen. John Johnston und L. H. Adams. Centr. Min. (In press.) 



A German translation of "Observations on the Daubree experiment and 

 capillarity in relation to certain geological speculations." (J. Geol., 1914). 

 Reviewed under No. 39 above. 



(41) Water and the magmatic gases. iVrthur L. Day and E. S. Shepherd. J. Wash. 



Acad. Sci., 3, 4.57-463, 1913. 

 This paper is chiefly concerned with the identification of and the reactions 

 between the gaseous ingredients set free by the liquid lava at Kilauea during 



