558 COLLECTING AND PRESERVING SPECIMENS 



To PRESERVE WOODEN LABELS. Thoroughly soak the pieces of 

 wood in a strong solution of copperas (sulfate of iron) ; then lay 

 them, after they are dry, in lime-water. This causes the formation of 

 sulfate of lime, a very insoluble salt, in the wood. 



BLACK INK FOR ZINC LABELS. Verdigris, 1 ounce ; sal am- 

 moniac, 1 ounce ; lampblack, \ ounce ; rain-water, If pint. Mix 

 in an earthenware mortar or jar and put up in small bottles. To be 

 shaken before use and used with a clean quill pen on bright zinc. 



Jars for Specimens 



The jars, bottles, or boxes in which specimens are kept should be 

 tight, to prevent evaporation, to keep out dust and mold, and to 

 protect from insects. There are specially made museum jars of many 

 attractive patterns. Four-sided fruit-jars with covers held by lever 

 fastenings are also excellent. If one cannot secure such receptacles 

 as these, he may prepare old bottles, and then fasten covers over 

 them. Following are old methods of cutting bottles in two : 



1. Pass five or six strands of coarse packing-twine round the bottle 

 on each side of the line where you want it divided, so as to form a groove 

 I inch wide; in this groove pass one turn of a piece of hard-laid 

 white cord, extend the two ends, and fasten to some support. Saw 

 the bottle backwards and forwards for a short time ; after a minute's 

 friction, by a side motion of the bottle throw it out of the cord into a 

 tub of water, and then tap on the side of the tub and the bottom 

 will fall off. 



2. Fill the bottle the exact height you wish it to be cut, with oil of 

 any kind ; dip, very gradually, a red-hot iron into the oil. The glass 

 suddenly chips and cracks all round, then the upper surface may be 

 lifted off at the surface of the oil. 



3. For cutting off bottoms of bottles, make a slight nick with a 

 file, and then mark round with a streak of ink where you want it to 

 come off. Make an iron red-hot and lay it on the nick. This will 

 cause it to expand and crack ; then, by moving the rod round, the 

 crack will follow. 



