430 Mr. C. Tomlinson on a new Variety of 



When a column of turpentine is used, a drop of oil of cubebs 

 descending in it, opens into widely expanding transparent rings, 

 which break up into small rings and festoons. A drop of kreo- 

 sote also separates into two or three transparent rings, which 

 break up into smaller ones, connected by fine lines of a peculiar 

 dull opake white colour. A drop of carbolic acid presents 

 similar phenomena, only the lines are glassy and transparent 

 throughout. A drop of camphorated spirit forms a veil, from 

 which descends a multitude of spirit-globules, and the camphor 

 disappears by solution. The oils of cloves and cinnamon also 

 make good figures. 



In pyroligneous ether, the oils of rosemary and lavender, as 

 also kreosote, formed rings and festoons ; the oil of verbena the 

 same, only they were chalky and persistent. Several essential 

 oils formed beautiful rolling rings before splitting up, such 

 as the oils of cloves, cajuput, chamomile, carraway, as also 

 benzole and carbolic acid. Water flashed into a ring and de- 

 scended, expanding and rolling on its curved axis, after the 

 manner of phosphide of hydrogen. A drop of hydrochloric 

 acid and of ammonia did the same. The oils of bergamot, 

 patchouli, origanum, and camphorated spirit formed figures 

 after the type of the cochineal solution in water, only instead of 

 dropping a third set of rings from the second set, oblate sphe- 

 roids were dropped. The oil of juniper descended as a sphere, 

 as did also turpentine, only the latter, having reached the bottom, 

 ascended slowly like a balloon in air. Olive and croton oils 

 formed flattened spheroids, the latter oil yielding much flatter 

 ones than the former. 



In a column of ether, if the drops did not immediately enter 

 into solution, they formed very beautiful rolling rings. The 

 hydrocarbons of mint and thyme were very fine; benzole, tur- 

 pentine, and cajuput were also particularly good ; a drop of tur- 

 pentine descends rapidly as a waving, trembling, rotating ring, 

 and disappears about two- thirds down. An attempt has been 

 made to represent some of these rings in the Plate. A drop 

 of the bright red tincture of cochineal forms good rolling rings 

 in ether, but the colour changes to purple even before the drop 

 reaches the surface of the ether. 



Having obtained these rolling rings in ether, I had no diffi- 

 culty in producing them in a tall column of water on a larger 

 scale, by allowing drops of a saturated solution of common salt 

 to fall on the surface from a dropping tube. A strong solution 

 of nitrate of copper also answered very well. 



I was talking over the subject of these rolling rings with my 

 friend Professor Miller, and expressing my opinion that they 

 explained perfectly the rolling motion of the phosphuretted hy- 



