Mr. C. Tomlinson on the Cohesion-Figures of Liquids. 361 



drop, instead of diffusing over the surface of the adhesion liquid, 

 sinks into it and diffuses through it. For this purpose a column 

 of liquid in a cylindrical glass is employed. When water is used, 

 a few drops of a strong solution of ammonia, or of oxalate of 

 ammonia, or of alum are added, for the purpose of throwing down 

 the lime, and also of assisting in the development of the figure. 

 A strong solution of cochineal in water forms a figure which is 

 typical of a number of cases of this kind of diffusion. A 

 single drop on the surface sinks down, opens into a ring, which 

 becomes depressed at two opposite points, and lets down lines 

 with other rings attached to them; while each ring, at 90° 

 from the point of attachment of each line, lets fall two other 

 lines with a ring attached, which ring in like manner, from 

 two points 90° distant from the line, lets fall other lines ; and 

 in this way the figure is developed slowly and symmetrically. 

 Oil of lavender in a column of spirits of wine behaves in a simi- 

 lar manner, only the figure is much more complicated and 

 crowded. A drop of fousel oil in a column of paraffin oil passes 

 through some complicated changes resulting in a kind of pointed 

 dome, the lower edge of which is cut into four symmetrical 

 arches ; from the springing of each pair of arches a line is let 

 down, and from the extremity of this proceeds four smaller 

 domes similarly arched, and letting down four other lines and 

 four other still smaller domes, forming a figure which lasts a 

 considerable time, exciting surprise in all who have seen it by 

 the kind of architectural symmetry produced. Figures of another 

 type are formed in columns of benzole, of ether, &c. In some 

 cases very perfect rolling rings are formed, for the details of 

 which I must refer to my paper, my business today being to 

 point out a variety of other forms of cohesion-figures by submer- 

 sion; for which purpose cylindrical columns of cocoa-nut oil, 

 castor oil, paraffin, spermaceti, white wax, lard, and olive oil 

 were used as in the case of cohesion -figures on the surface. Heat 

 must be employed when necessary; but the best results are 

 obtained with the cold oils, or with only just a sufficient amount 

 of heat to render the solid substances fluid. Indeed the figures 

 vary considerably with considerable differences of temperature, 

 not only with substances which require to be melted, but with 

 oils which are fluid at ordinary temperatures. 



Cocoa-nut Oil. — When a column was at about 160°, a drop of 

 patchouli oil flashed out into rings and festoons. Oil of cloves 

 formed a wide ring, from which proceeded numerous festoons 

 and small rings ; oil of cinnamon two or three large rings and 

 festoons. Oil of cummin descended as a riband with a globule 

 attached, from which proceeded upwards a dome cut into arches 

 with lines terminated by knobs at the springing of each pair of 



Phil Mag. S. 4. Vol. 28. No. 190. Nov. 1864. 2 B 



