a half ounce of cyanide of potassium; on this pour water to the depth of about three-fourths of an inch, and then sprinkle in and mix gently and evenly enough plaster of Paris to form a thick cream, which will set in a cake in the bottom of the vial.  Let it stand open an hour to set and dry, then wipe out the inside of the vial above the cake and keep it corked.  This is the regular entomological poison bottle, used everywhere.  An insect put in it dies quietly at once.  It will last several months.

These two tools, the net and the poison bottle, are your catching and killing instruments.  You know where to look for butterflies.  Moths are vastly more numerous, and while equally beautiful, present more varieties of beauty than butterflies.  They can be found by daylight in all kinds of weather, in the grass fields, in brush, in dark woods, sometimes on flowers.  Many spend the daytime spread out, others with close shut wings on the trunks of trees in dark woods.  The night moths are more numerous and of great variety.  They come around lamps, set out on verandas in the night, in great numbers.  A European fashion is to spread on tree trunks a sirup made of brown sugar and rum, and visit them once in a while at night with net and lantern.  Catch your moth in the net, take him out of it by cornering him with the open mouth of your poison bottle, so that you secure him unrubbed.

Now comes the work of stretching your moths.  This is easy, but must be done carefully.  Provide your own stretching boards.  These can be made anywhere with hammer and nail and strips of wood.  You want two flat strips of wood about seven-eighths or three-fourths of an inch thick and eight to fourteen inches long, nailed parallel to each other on another strip, so as to leave a narrow open space between the two parallel strips.  Make two or three or more of these, with the slit or space between the strips of various widths, for large and small moths and butterflies.  Make as many of them, with as various widths of slit, as your catches may demand.  Take your moth by the feet, gently in your fingers, put a long pin down through his body, set the pin down in the slit of the stretching board, so that the body of the moth will be at the top of the slit and the wings can be laid out flat on the boards on each side.  Have ready narrow slips of white paper.  Lay out one upper wing flat, raising it gently and carefully by using the point of a pin to draw it with, until the lower edge of this upper wing is nearly at a right angle with the body.  Pin it there temporarily with one pin, carefully, while you draw up the under wing to a natural position, and pin that.  Put a slip of paper over both wings, pinning one end above the upper and the other below the under wing, thus holding both wings flat on the stretching board.  Take out the pins first put in the wings and let the paper do the holding.  Treat the opposite wings in the same way.  Put as many moths or butterflies on your stretching board as it will hold, and let them remain in a dry room for two, three, or more days, according to size of moths and dampness of climate.  Put them in sunshine or near a stove to hasten drying.  When dry, take off the slips of paper, lift the moth out by the pin through the body, and place him permanently in your collection.—­Wm. C. Prime, in N.Y.  Jour. of Commerce.