464 SCIENTIFIC RECORD FOR 1882. 



an lionr. Then a capillary tube entering the bottom of the vessel is 

 connected by a rubber tube with a moveable vessel of colored alcohol. 

 As this alcohol enters the vessel through the capillary tube it rises as 

 a thin spiral thread, spreading into fine tree-shaped figures on reaching 

 the lighter liquid. If the heavier liquid be used in place of the alcohol, 

 umbrella-shaped figures are produced. {Nature, July, xxvi, p. 309 ; J. 

 Phys., November, II, i, p. 520.) 



Wrightson and Koberts have communicated further results on the 

 density of liquid metals obtained with their oncosimeter. They obtained 

 for copper 8.217, lead 10.37, tin 7.025, zinc 6.487, silver 9.51, iron (Xo. 4 

 foundry, Cleveland) 6.88. {Nature, February, 1882, xxv, p. 355.) 



The specific gravity of melted steel has been determined by Alexijew 

 by Petruschewsky's method. An open porcelain tube was immersed in 

 liquid steel to a given depth, and air was forced into it until it bubbled 

 up through the melted mass. By means of an attached manometer, 

 the pressure was read off; and knowing this and the depth the density 

 is easily computed. It was found to be 8.05, and therefore greater than 

 solid steel. {Nature, June, 1882, xxvi, p. 138.) 



Angstrom has studied the increase in volume produced when water 

 absorbs a gas, using for this purpose air, nitrogen, carbonous oxide, 

 oxygen, hydrogen, and carbon dioxide. For each of these gases the 

 increase in -volume was proportional to the quantity of gas absorbed. 

 Calling the increase in volume which a liquid undergoes in absorbing 

 unit volume of a gas — the coefficient of expansion by absorption, he finds 

 this value to be for N 0.00145, air 0.00140, CO 0.00127, O 0.00115, H 

 0.00106, CO2 0.00125, HCl 0.00097, NH3 0.00077, and SO2 0.00091. ( Wied. 

 Ann., V, XV, p. 297; J. Phys., June, II, i, p. 288.) 



Leconte has called attention to the very general error in physical 

 text books concerning the attraction and repulsion of small floating 

 bodies, and has given the true theory of the phenomenon founded upon 

 the surface tension of the liquid, and involving the two fundamental 

 principles of capillarity, viz, 1st, that the elastic reaction is inversely 

 l^roportioual to the radius of curvature of the meniscus; and 2d, that 

 the same contractile reaction tends to reduce the perimeter to the 

 smallest which can be inclosed by its actual boundary. {Am. J. Sci., 

 December, III, xxix, p. 416.) 



Plateau has described to the Belgian Academy a capillary arrange 

 ment which seems at first capable of realizing a perpetual motion. A 

 capillary tube is inserted obliquely in distilled water so that the latter 

 nearly fills it. Into this liquid column at the top dips the small orifice 

 of another tube, which reaches a little way in the same oblique direc 

 tion, then turns downwards, the vertical portion being wider, and not 

 reaching the water. Suppose this bent tube filled with water. It then 

 forms a siphon, the shorter branch of which is immersed in a liquid in 

 equilibrium, while the longer descends several centimeters below the 

 surface of that liquid. It appears, therefore, as though the water should 



