Mr. C. Tomlinson on the Cohesion-Figures of Liquids. 359 



then settles down into a charming star-like figure surrounded 

 by rings and iridescent colours, and a sharp boundary line. In 

 one case the central boss slipped off the figure, leaving the disk 

 with its iridescent rings, &c. complete. 



White Wax. — With the surface at 142°, ether solidified a por- 

 tion which rushed wildly about. Alcohol solidified a portion in 

 the form of a ring, which immediately broke up and was dispersed 

 in radial lines, while the alcohol settled down into a small 

 sharply- defined disk. At a higher temperature, such as 170°, a 

 drop of alcohol will solidify a cup-shaped cavity for its reception ; 

 but if the drop be held for a short time over the surface so as to 

 become warmed, it at once subsides into a sharp well-turned disk. 

 Lard. — Good figures are formed on the surface of melted lard 

 with ether, alcohol, and the oils of turpentine, savin, paraffin, 

 lavender, and some others. A drop of camphorated spirit 

 formed a very beautiful figure, some idea of which may be 

 gathered from fig. 7. The rippled concentric circles display 

 several of the orders of Newton's, or rather of Nobilr's rings. 



Olive Oil. — A fresh flask of the variety of this oil known as 

 extra sublime, was opened for the purpose, and portions of it 

 were poured into the ordinary 4-inch cohesion-figure glasses. It 

 answers admirably as an adhesion surface at ordinary tempera- 

 tures. A drop of ether produces a small beautiful figure, con- 

 sisting of a disk surrounded by rays. Alcohol forms a disk about 

 3 inches in diameter; the drop diffuses well, and the disk is 

 perfectly circular, with a central boss. Iridescent rings contain- 

 ing the colours of four or five orders fringe the edge of the disk 

 in broad bands, and outside this large disk is a fainter and more 

 shadowy disk. When the figure is fully developed, it rapidly 

 opens, and closes in upon the centre like a curtain being drawn 

 in, and so vanishes, leaving no trace behind. Camphorated 

 spirit (fig. 6) is even more beautiful and persistent than alcohol ; 

 the iridescent rings are dentated, and this adds greatly to their 

 beauty ; the film, which is of a very large size, retreats slowly 

 inwards to the centre, leaving the camphor in the form of minute 

 dots disposed in radial lines; these lines in their turn retreat 

 towards the centre, where the camphor collects in the form of a 

 flat ring. 



Benzole forms a large plain disk with a cavity in the centre. 

 Turpentine, cajuput, and lavender also form disks; but the 

 most curious figure is given by a drop of pure wood-spirit. It 

 flashes out into a disk about 1| inch in diameter, then retreats 

 inwards with the elasticity of a spring, leaving a delicate fringe 

 made up of innumerable small" dots; the disk then becomes 

 toothed at the edge so as to give it the appearance of a small 

 circular saw ; the disk retreats inwards, and the point of each 



