boiling mass may be allowed to slip from a spoon in a sheet, in a step called "sheeting". At the "crack" stage, syrup from boiling sugar may be dripped from a spoon, causing it to break with a snap when chilled. When boiled to 240 °F. and poured from a spoon, sugar forms a filament, or "thread". Hot syrup is said to "pearl" when it forms such a long thread without breaking when dropped from a spoon. Used for stirring, a spoon is passed through a substance with a continued circular movement for the purpose of mixing, blending, dissolving, cooling, or preventing sticking of the ingredients. Mixed drinks may be "muddled" by working a spoon to crush and mix ingredients such as mint and sugar on the bottom of a glass or mixer. Spoons are employed for mixing certain kinds of powder into water to make a sweet or nutritious drink. A spoon may also be employed to toss ingredients by mixing them lightly until they are well coated with a dressing. For storage, spoons and knives were sometimes placed in paired knife boxes, which were often ornate wooden containers with sloping top, used especially during the 18th century. On the table, an ornamental utensil called a nef, shaped like a ship, might hold a napkin, knife and spoon. Language and culture Spoons can be used as a musical instrument. To spoon-feed oneself or another can simply mean to feed by means of a spoon. Metaphorically, however, it often means to present something to a person or group so thoroughly or wholeheartedly as to preclude the need of independent thought, initiative or self-reliance on the part of the recipient; or to present information in a slanted version, with the intent to preclude questioning or revision. Someone who accepts passively what has been offered in this way is said to have been spoon-fed. A spoonful—the amount of material a spoon contains or can contain—is used as a standard unit of measure for volume in cooking, where it normally signifies a teaspoonful. It is abbreviated coch or cochl, from Latin cochleare. "Teaspoonful" is often used in a similar way to describe the dosage for over the counter medicines. Dessert spoonful and tablespoonful may also be found in drink and food recipes. A teaspoon holds about 5ml and a tablespoon about 15 ml. The souvenir spoon generally exists solely as a decorative object