[pg 80]
Accessories such as glass rods, plates, tubing of various diameters, thin copper wire, and an aluminium plate for the spheroidal state, can be obtained from any dealer in apparatus; and the same applies to clamp-stands for holding funnels, etc.
Water.—Ordinary tap-water suffices for all the experiments described, and for work with films and globules is superior to distilled water, which often possesses a surface so greasy as to retard or even entirely prevent the desired result. All experiments conducted on the surface of water should be performed in a clean vessel which has been rinsed out several times with tap-water before filling.
Lantern Projection.—In demonstrating the phenomena to an audience, a lantern may be used to advantage. It should be of the type now procurable, which is arranged for the projection of experiments conducted either in a horizontal or vertical position, by the use of the electric arc or other suitable source of light. Flat-sided vessels are essential for the successful projection of views of objects in a vertical position; and for showing globules, etc., on the surface of water, better definition is secured if cells with plate-glass bottoms are used instead of vessels made of a single piece of glass. The author has generally used a “Kershaw” lantern for lecture purposes, with quite satisfactory results. This lantern may also be adapted for projecting solid objects by reflected light—as, for example, a hot plate on which a spheroid of water is floating ([Fig. 34]). The contrivance known as the “Mirrorscope” may also be used, with slight modification, for producing a magnified image of solid objects on the screen.
[pg 81]
INDEX
A PAGE
Aceto-acetic ether, automatic drops of, . . . [pg 37]_
” columns of, . . . . . . [pg 44]_
Aniline, automatic drops of, . . . . [pg 33]_