Page:On the various forces of nature and their relations to each other.djvu/63

Rh want this afterwards to look to and examine its internal condition)—and here is some of the same sort of glass differing only in its power of cohesion, because while yet melted it has been dropped into cold water [exhibiting a "Prince Rupert's drop" (fig. 13)]; and if I take one of these little tear-like pieces and break off ever so little from the point, the whole will at once burst and fall to pieces. I will now break off a piece of this. [The Lecturer nipped off a small piece from the end of one of the Rupert's drops, whereupon the whole immediately fell to pieces.] There! you see the solid glass has suddenly become powder—and more than that, it has knocked a hole in the glass vessel in which it was held. I can shew the effect better in this bottle of water; and it is very likely the whole bottle will go. [A 6-oz. vial was filled with water, and a Rupert's drop placed in it, with the point of the tail just projecting out; upon breaking the tip off, the drop burst, and the shock being transmitted through the water to the sides of the bottle, shattered the latter to pieces.]

Here is another form of the same kind of