DIVISIBILITY, that general property of bodies by which their parts or component particles are capable of sep aration. Numerous examples of the division of matter, to a degree almost exceeding belief, may be easily in stanced. Thus glass test-plates for mi croscopes have been ruled so fine as to have 225,000 spaces to the inch. Cotton yarn has been spun so fine that one pound of it extended upward of 1,000 miles, and a Manchester spinner is said to have attained such a marvelous fineness that one pound would extend 4,770 miles. One grain of gold has been beaten out to a surface of 52 square inches, and leaves have been made 367,500 of which would go to the inch of thickness. Iron has been reduced to wonderfully thin sheets. Fine tissue paper is about the 1,200th part of an inch in thickness, but sheets of iron have been rolled mu h thinner than this, and 's fine as one 4,800th part of an inch 25-VOI.
in thickness. Wires of platinum have been drawn out so fine as to be only the 30,000th part of an inch in diameter.
Human hair varies in thickness from the 250th to the 600th part of an inch. The fiber of the coarsest wool is about the 500th part of an inch in diameter, and that of the finest only the 1,500th part. The silk line, as spun by the worm, is about the 5,000th part of an inch thick; but a spider's line is only the 30,000th part of an inch in diam eter; insomuch that a single pound of this attenuated substance might be suf ficient to encompass our globe. A single grain of the sulphate of copper, or blue vitriol, will communicate a fine azure tint to five gallons of water. In this case the sulphate must be attenuated at least 10,000,000 times. Odors are ca pable of a much wider diffusion. A single grain of musk has been known to perfume a large room for the space of 20 years.