438 Mr. C. Tomlinson on the Spheroidal Condition 



tures. For example, if a single drop of a liquid, such as an 

 essential oil, be gently deposited from the end of a glass rod on 

 the surface of perfectly clean water in a chemically clean glass, it 

 forms a characteristic film or cohesion-figure ; but if a second 

 drop be gently delivered to the surface of the film, it will rest or 

 roll about upon it, without contact, in the spheroidal form. 



In a note communicated by M. Meunier to the Academy of 

 Sciences at Paris (Comptes Rendus, August 17, 1863), the results 

 of some experiments are given on the globular form that liquids 

 may assume on surfaces of their own kind. M. Meunier's mode 

 of manipulating is to take up alcohol, for example, in a pipette 

 and drop it upon the surface of alcohol. The globules formed 

 last but a very short time ; they roll about on the surface with- 

 out being in contact, as was ingeniously proved by dropping 

 alcohol on tincture of iodine, when the globules during their 

 brief existence did not become coloured. Another method was 

 to dip a glass rod .into the liquid so as to take up a sufficient 

 quantity to deposit a drop on its surface. In this way all liquids 

 formed globules with more or less difficulty ; but there was no 

 difficulty if the liquid were first covered with a layer of another 

 liquid not miscible with it. M. Meunier' s conclusion is that all 

 liquids possess the property of passing into the spheroidal state. 



M. Meunier does not seem to have pursued the subject further ; 

 had he done so, he would probably have noticed other circum- 

 stances which seem to me to deserve attention, if only as further 

 illustrations of that wonderful property of cohesion in liquids, of 

 which the spheroidal state is an example. If, for example, the 

 experiment be made with essential oils, and the duration of the 

 liquid in the spheroidal state be noted, we may, I think, obtain 

 a rough approximative method of determining the age of an 

 essential oil ; for I have found that the fresher the oil the greater 

 is its cohesive force as expressed by its duration in the spheroidal 

 form at common temperatures. 



For example, oil of turpentine, as purchased at an oil and 

 colour shop, was examined in the following manner. Three glass 

 capsules, No. 1, No. 2, and No. 3, each about 2J inches in dia- 

 meter, were nearly filled with water and placed in the mouths of 

 test-glasses before the light. A drop of the turpentine was de- 

 posited on the surface of each from the end of a glass rod ; the 

 drop in each case flashed out into a film which nearly covered 

 the surface of the water. A second drop of turpentine was gently 

 delivered to the surface of the film No. 1, when it formed 

 a spheroid, the duration of which was measured in seconds. 

 When the spheroid vanished, a similar one was formed on the 

 film in No. 2, and its duration measured; and so for No. 3. 

 Eight observations were taken on each film. 



