1797. The written number-stick varies in form, size, and materials. The simplest kind is a flat piece of lath, smoothed and pointed with the knife, and either painted, or more commonly rubbed on the face with white lead at the time of using, with numbers corresponding with those of genus, species, and varieties written on it. Sometimes types and printers' ink are used: when the paint is dry, common ink or black paint is also made use of; and, in some cases, the number is impressed by a cold type, or burnt in by one heated to redness. A little white lead rubbed on with the finger, and the name immediately written with a hard black lead pencil, will last as long as the wood, and is, on the whole, the best mode. Various sizes are used, from laths formed with the knife, three inches long and half an inch broad, to pieces sawed out of deal, two or three inches broad, and from eighteen inches to three feet long; the upper part painted white, and the lower part pitched, charred, or coated with some preservative liquid, for durability. With respect to materials, fir deal is most commonly used; but oak boards, or old oak spokes, are occasionally made use of in botanic gardens.