attraction presented to the water by the wetted sides of the 
interior of the tube. A simpler illustration was also referred 
to — the placing two flat pieces of glass against each other, 
and resting the lower edge in water, whereupon a watery 
film is drawn up between the two surfaces. Having shown 
the principle of capillary attraction in the well-known case of 
a single tube, Mr. Pearsall now exhibited it on a large scale. 
A hemisphere of fine wire gauze was made to float on water, 
by simply establishing a watery film in all the interstices by 
means of immersion, the resistance of the film to the inclosed 
atmosphere being so great as to keep the copper hemisphere 
afloat, and sustain a pendant weight of one ounce. The con- 
verse of this experiment was shewn by filling a wire gauze 
sphere with water, and keeping it in by the mere strength of 
a similar film procured by immersion. 
It was thus proved that a thin plate of liquid, even water, 
(and that might be made up of many small plates), possessed 
a force that could retain imprisoned volumes of air and gases 
that could not escape, even if assisted by the pressure of 
liquids in bulk, and that the thin film of liquids could also 
retain cubic inches of fluids suspended, and on all sides sur- 
rounded by the atmosphere. After shewing the importance 
of this to explain the retention of air or liquids by mem- 
branes, and so causing diseases, and of the retaining power 
exercised by the structure of strata to retain liquid and 
gases, he shewed an application of this power on the large 
scale, and, as some might call it, of practical application and 
suggestion. The experimenter took an ordinary pillow- 
case, well wetted, and inflated it with atmospheric air, when 
it was observed that all the interstices of the threads being 
occupied by water in the form of film, the object, thus 
rendered to a surprising extent air-tight, became such a 
resistant buoy as to be capable of floating a person, or several 
persons, on the water. This expedient, it was suggested, 
